11 - Appendix A Flashcards
(278 cards)
1
Q
What supplementation is most likely to have prevented the condition of the 10-year-old child with multiple bruises and petechiae?
A
C. Ascorbic acid
Ascorbic acid (Vitamin C) is essential for collagen synthesis and its deficiency can lead to symptoms like those seen in scurvy.
2
Q
In a patient who underwent Roux-en-Y gastric bypass surgery, which process is most likely to cause explosive diarrhea?
A
A. Transit time of food in the gut
The surgery alters gut anatomy, leading to rapid transit and malabsorption.
3
Q
What is the most appropriate next step in management for a patient with factor VIII deficiency whose bleeding is not controlled?
A
D. Send an assay for FVIII inhibitors
FVIII inhibitors can develop in patients with hemophilia and can prevent effective treatment.
4
Q
What is the most likely cause of chronic diarrhea and failure to thrive in a 6-month-old infant after introducing solid foods?
A
B. Sucrase deficiency
Sucrase deficiency can lead to malabsorption of sugars, causing diarrhea.
5
Q
What test is most appropriate for a woman experiencing prolonged postpartum bleeding with symptoms of easy bruisability?
A
C. vWF level as you suspect von Willebrand disease
von Willebrand disease is characterized by bleeding symptoms and abnormal PTT.
6
Q
In a patient with cholera, what mechanism is involved in pathogenesis?
A
A. Overactivation of the alpha subunit of Gs-proteins
This leads to increased cAMP levels and secretion of fluids in the intestines.
7
Q
What defect is most likely present in a patient with acute lymphocytic leukemia experiencing bleeding gums?
A
A. Platelets
The patient’s bleeding symptoms suggest an issue with platelet function or quantity.
8
Q
What is the most appropriate next step in evaluation for a patient whose prothrombin time suddenly drops to normal while on warfarin?
A
C. Obtain a detailed dietary history
Changes in diet, especially vitamin K intake, can affect warfarin efficacy.
9
Q
What accounts for muscle weakness in a patient with abnormal glucose tolerance and high plasma ACTH?
A
D. Gluconeogenesis
Increased gluconeogenesis can lead to muscle wasting and weakness.
10
Q
What is the most appropriate next step in management for a woman with profound weakness and low blood pressure after losing her asthma medications?
A
C. Hydrocortisone
This patient likely has adrenal insufficiency due to abrupt cessation of steroid therapy.
11
Q
What is the most likely diagnosis for a woman with low hemoglobin, high methylmalonic acid, and high homocysteine levels?
A
B. Vitamin B12 deficiency
These lab findings are characteristic of megaloblastic anemia due to B12 deficiency.
12
Q
Which factor is most likely to be decreased in a patient with vitamin B12 deficiency?
A
B. Intrinsic factor
Intrinsic factor is necessary for vitamin B12 absorption in the intestine.
13
Q
What is the most likely explanation for prolonged PT and PTT in a young woman with heavy menstrual bleeding and a diet lacking in nutrients?
A
C. Vitamin K deficiency
Vitamin K is crucial for the synthesis of clotting factors, and deficiency can lead to prolonged bleeding.
14
Q
What metabolite is most likely to lead to the development of cataracts in a newborn with jaundice and hepatomegaly?
A
D. Galactitol
Galactitol accumulates in galactosemia and can lead to cataract formation.
15
Q
What is the most appropriate intervention for a 10-month-old infant with severe anemia and crystalline sediment in urine?
A
B. Uridine
Uridine may help in conditions like hereditary orotic aciduria.
16
Q
What is most likely to be increased in a 1-year-old child on a BRAT diet presenting with edema and lethargy?
A
D. Oxidative stress
A BRAT diet is low in nutrients and can lead to deficiencies that increase oxidative stress.
17
Q
What mechanism is initiated in a person climbing to a high altitude with symptoms of headache and light-headedness?
A
B. Reabsorption of bicarbonate in the kidney to alleviate the pH imbalance
This compensates for respiratory alkalosis due to decreased oxygen levels.
18
Q
What is the most likely diagnosis for an elderly woman with low hemoglobin and glossitis, with low vitamin B12 and folate levels?
A
C. Autoimmune atrophic gastritis
This condition can lead to decreased intrinsic factor and subsequent vitamin B12 deficiency.
19
Q
What laboratory study is most consistent with preoperative evaluation for a patient with von Willebrand disease?
A
D. vWF antigen level
This helps assess the severity of von Willebrand disease before surgery.
20
Q
What is most likely the cause of facial dysmorphic features in a child with microcephaly and atypical facies?
A
A. Impaired neural crest movement
Impaired neural crest cell migration can lead to various congenital facial anomalies.
21
Q
What is the bilirubin level in a 15-year-old male with an elevation in bilirubin but normal liver enzymes?
A
Total bilirubin is 2.5 mg/dL and direct bilirubin is 2.1 mg/dL.
This suggests a possible conjugated hyperbilirubinemia.
22
Q
What is the most likely cause of facial dysmorphic features in a patient with an um, thin upper lip, and narrow, small eyes?
A
Impaired neural crest movement
23
Q
In a 15-year-old boy with an elevation in bilirubin and normal AST/ALT, which defect is most likely?
A
UDP-glucuronosyltransferase (UGT1A1)
24
Q
What is the most appropriate next step in the management of jaundice in a 4-day-old breast-fed male newborn with a total bilirubin concentration of 7 mg/dL?
A
Continue breastfeeding
25
What is the most likely next step in the management of a 2-day-old neonate with total bilirubin of 15 mg/dL?
Administer hydration therapy
26
What is the most likely explanation for jaundice and upper right quadrant pain in a 36-year-old male patient with sickle cell anemia?
Biliary tract obstruction by pigment stones
27
What is the most likely explanation for gastrointestinal symptoms in a 16-year-old boy presenting with diarrhea, weight loss, and a chronic nonproductive cough?
Defective secretions due to a mutation in the CFTR gene
28
What pattern of liver function tests would most likely predict the condition of a 22-year-old female with jaundice after returning from central West Africa?
29
What nutrient is most likely deficient in a 44-year-old man who underwent Roux-en-Y gastric bypass surgery and presents with weakness and macrocytic anemia?
Vitamin B12
30
Which blood test is most appropriate to assess liver’s synthetic metabolic function in a patient diagnosed with hepatitis C?
Albumin
31
What marker would most likely be elevated in a 78-year-old woman with shortness of breath and chronic diarrhea after ileum resection?
Methylmalonic acid
32
What is the most likely laboratory finding regarding a 26-year-old woman with weakness, fatigue, and mild dyspnea on exertion?
Increased total iron binding capacity
33
What is the most likely finding in a peripheral blood smear for a 16-year-old boy with a tremor and mild microcytic anemia?
Heinz bodies
34
What is the most likely categorization of the diarrheal illness in a 23-year-old woman with frequent small stools and urgency?
Inflammatory
35
What is the most likely mechanism of primaquine causing hemolysis in a 22-year-old male with dark stools and urine?
Increased levels of reactive oxygen species
36
What finding is most likely decreased in a 59-year-old female with joint pain and darkening skin?
Ferroportin
37
What laboratory finding is most likely in a 3-week-old child with hypoglycemia and hepatomegaly without ketosis?
Increased lactate
38
What is the most likely laboratory finding in a lethargic child with prolonged neonatal jaundice and partial response to phototherapy?
A low haptoglobin and elevated reticulocyte count
39
What is the most likely reason for fever and severe leg pain in a 5-year-old boy from a mountainous area with a family history of anemia?
He was playing soccer at a high altitude
40
What modulation is most likely to improve symptoms in a patient experiencing hypoxia-related symptoms?
Increased concentration of 2,3-BPG
41
What is the most appropriate next step for a disoriented patient with a history of alcoholism in the emergency department?
Intravenous administration of thiamine 100 mg
42
What change is most likely to occur in a 22-year-old male with symptoms of hemolysis after taking primaquine?
Increased transport of albumin-bound bilirubin to the liver
43
What is the most appropriate diagnostic test for a 6-year-old child diagnosed with celiac disease?
Antitissue transglutaminase antibodies
44
What is the least likely explanation for persistent elevated phenylalanine levels in a newborn diagnosed with phenylketonuria?
The level of phenylalanine is depressed in the brain resulting in a defect in neurotransmission
45
What is the most appropriate diagnostic study for a 20-year-old female experiencing bloating and urgency at stool?
46
What are the symptoms of the patient experiencing repetitive bowel movements after meals?
Worsening for over a year, chronic intermittent constipation as a teenager, stable weight, some stress, normal physical examination, normal blood count, chemistry, and urinalysis results.
47
What is the most appropriate diagnostic study for the patient with bowel movement issues?
Careful dietary history.
48
What are the key concerns for the 6-year-old child brought in for neuropsychological evaluation?
Behavioral problems, emotional concerns, poor school performance, developmental delays, less than 5th percentile for height and weight.
49
What is the most likely diagnosis for the 6-year-old child with a history of prenatal alcohol exposure?
Fetal alcohol syndrome.
50
What are the symptoms of the 10-day-old infant admitted to the neonatal intensive care unit?
Lethargy, feeding difficulties, decreased muscle tone, afebrile, hepatomegaly, acidotic, hypoglycemic, elevated serum ammonia level, abnormal serum carnitine levels, organic acids in urine, elevated BUN.
51
What is the most likely working diagnosis for the 10-day-old infant?
Glycogen storage disease.
52
What condition did the 14-year-old boy experience after waking up with weakness in the left arm?
Right middle cerebral thrombosis.
53
Which enzyme deficiency is suspected in the 14-year-old boy with sudden arm weakness?
Cystathionine beta synthase.
54
What symptoms did the 14-month-old girl exhibit that led to her evaluation?
Progressive muscle weakness, seizure, nystagmus, exaggerated hyperreflexia, cherry-red spot on retina.
55
What is the most likely working diagnosis for the 14-month-old girl?
Tay-Sachs disease.
56
What laboratory findings were observed in the 6-year-old boy with excruciating pain?
Hemoglobin 5.7, hematocrit 17.1, leukocytes 1300, platelets 52,000, bone marrow aspirate shows macrophages with a wrinkled tissue paper appearance.
57
This patient most likely has an accumulation of which substrate?
Sphingomyelin.
58
What condition is suggested by the 14-year-old boy's symptoms after strenuous exercise?
Muscle cramps and fatigue, myoglobinuria, hyperuricemia, increased serum bilirubin.
59
What enzyme deficiency is likely in the 14-year-old boy with exercise-related symptoms?
Muscle phosphofructokinase.
60
What are the clinical features of the 9-year-old female patient?
Diabetes, bilateral sensorineural hearing loss, mental and language disorder, bilateral cataracts, retinitis pigmentosa, seizures, pyramidal syndrome, calcification of basal ganglia.
61
What mechanism explains the 9-year-old female patient's condition?
Mutation in mitochondrial tRNA.
62
What are the symptoms of the 5-year-old female with diarrhea and abdominal distention?
Diarrhea, abdominal distention, anemia, increased abdominal volume after eating.
63
What is the most likely diagnosis for the 5-year-old female with positive Sudan staining for fecal fat?
Cystic fibrosis.
64
What enzyme deficiency may explain the symptoms in the 5-year-old girl with diarrhea following gastroenteritis?
Acetyl CoA carboxylase.
65
What condition is suggested by the 5-week-old child with vomiting, diarrhea, jaundice, and failure to thrive?
Classic galactosemia.
66
What is the most likely cause of black pigmentation in gallstones of the 20-year-old male?
Deficiency of pyruvate kinase.
67
What are the symptoms of the 1-month-old child with megaloblastic anemia?
Refractory to cobalamin and folate supplementation, pale, small for age, feeding difficulties.
68
What enzyme deficiency is suggested for the 1-month-old child with elevated BUN and crystals in urine?
Ornithine transcarbamylase (OTC).
69
What initial diagnostic study is appropriate for the 55-year-old female with symptoms of fatigue and depression?
Thyroid-stimulating hormone.
70
What vitamin acts as a coenzyme for enzymes in the 35-year-old male with acute confusion and vision loss?
Thiamine.
71
What is the next likely laboratory test for the 40-year-old man with melena and anemia?
Serum gastrin level.
72
What is the most likely mechanism of disease for the 2-year-old male with self-mutilating behavior?
Decreased salvage of purines.
73
Which enzyme deficiency is likely for the 2-year-old male with increased uric acid production?
Hypoxanthine-guanine phosphoribosyltransferase.
74
What is the most appropriate treatment for urate-lowering therapy in the 2-year-old male?
Allopurinol.
75
What is the most appropriate treatment for urate-lowering therapy in this patient’s care?
C. Allopurinol
76
What is the most likely enzyme deficiency in the 25-year-old female patient?
D. Glucose 6-phosphatase
77
What is the most likely explanation for hyperuricemia in this patient?
C. Stimulation of AMP deaminase by decreased inorganic phosphate
78
What is the most appropriate next step to confirm the diagnosis in the 4-year-old child with abdominal pain?
C. CBC and iron panel
79
What laboratory findings are most likely to show in the 40-year-old woman with lethargy and cognitive changes?
C. An elevated TSH
80
What should be measured in the plasma of the 2-year-old girl with phenylketonuria?
C. Tyrosine
81
What is the most likely working diagnosis for the 37-year-old man with disorientation after consuming protein shakes?
C. von Gierke disease
82
What enzyme is most likely deficient in the 7-day-old infant with acidosis and seizures?
C. Propionyl-CoA carboxylase
83
What is the most appropriate next step in managing a 50-year-old man with methanol ingestion?
C. Administration of fomepizole
84
Which disease is most likely causing the clinical findings in the 1-month-old infant with hypotonia and failure to thrive?
A. Refsum disease
85
What is the most appropriate pharmacotherapy for the 19-year-old female with severe abdominal pain after binge drinking?
D. Thiamine
86
Which supplementation is the LEAST likely intervention for the 4-year-old male with developmental delay and elevated serum methionine?
C. Biotin
87
What enzyme deficiency is likely in the 1-month-old child with megaloblastic anemia refractory to supplementation?
B. Ornithine transcarbamylase (OTC)
88
What is the most accurate statement regarding the patient with an inflamed right elbow?
A. A radiograph of the elbow will show chondrocalcinosis.
89
What is the most likely explanation for hypoglycemia in the 45-year-old man with alcohol abuse?
A. Increased NADH/NAD ratio inhibiting gluconeogenesis
90
What is the most likely metabolic change after administering glucose and thiamine to the 45-year-old man?
B. Increase in triacylglycerol synthesis
91
What enzyme is deficient in the 45-year-old male with severe abdominal pain and elevated δ-aminolevulinic acid?
D. Porphobilinogen deaminase
92
What laboratory findings are most likely for the 3-year-old female found unresponsive with calcium oxalate crystals?
A. Increased anion gap
93
What is the underlying cause of the acid-base disorder in the 78-year-old female with elevated glucose?
[key learning term]
94
What is the normal range for Chloride in mEq/L?
95-105 mEq/L
95
What is the normal range for Bicarbonate in mEq/L?
22-28 mEq/L
96
What is the normal range for Glucose in mg/dL?
70-110 mg/dL
97
What is the normal range for BUN in mg/dL?
7-18 mg/dL
98
What is the normal range for Creatinine in mg/dL?
0.6-1.2 mg/dL
99
Which pathway is most likely the underlying cause of the patient’s acid-base disorder?
C. Amino acid degradation
100
What is the body mass index (BMI) of a 44-year-old man with a BMI of 35 kg/m²?
35 kg/m²
101
What blood pressure measurement indicates hypertension in a patient?
150/95 mm Hg
102
Which laboratory finding suggests a diagnosis of nonalcoholic steatohepatitis?
Elevated liver enzymes
103
What is the most likely initiating factor in the formation of plaque in the anterior descending coronary artery?
B. Endothelial damage
104
What is the significance of an AST/ALT ratio of 125/105 units/L in a 42-year-old male with hypertension?
Possible liver dysfunction or fatty liver disease
105
Which explanation is most likely for a patient with hypertension, obesity, and increased liver enzyme activity?
A. Decreased adiponectin levels
106
What laboratory study result is most likely for a patient who has exhausted insulin supplies and is experiencing increased thirst?
C. Intracellular potassium level is decreased
107
What is the most likely diagnosis for a 38-year-old male with a BMI of 31.5 kg/m² and blood pressure of 135/80 mm Hg?
D. Metabolic syndrome
108
Which metabolic pathway in the liver will have diminished activity in a patient with obesity and hypertension?
B. Decreased gluconeogenesis
109
What pathologic process is described in a 65-year-old man with type II diabetes experiencing vision problems?
B. Atherosclerosis
110
Which preliminary diagnosis is most likely for a woman with increased serum liver enzyme activity and a history of thiazide diuretic use?
D. Nonalcoholic steatohepatitis
111
What is the most likely reason exercise would improve laboratory findings in a patient with hypertension and obesity?
B. Activates AMPK pathway
112
What is the most likely cause of acute right quadrant pain in a 50-year-old woman with a history of similar attacks?
A. Obstruction of her cystic duct by a gallstone
113
What is the likely cause of symptoms in a 44-year-old female presenting with epigastric tenderness and pain after meals?
B. Cholecystitis
114
What defect is indicated by prolonged partial thromboplastin time (PTT) in a 16-month-old boy with bleeding tendencies?
A. Intrinsic clotting pathway
115
What is the underlying diagnosis for a 54-year-old man with jaundice, dark urine, and pale stools?
Enlarged head of the pancreas
116
What is the primary deficiency suggested by findings of hair, mucosal hemorrhage, bruising, and neuropathy in a child?
Vitamin C deficiency
## Footnote
These findings are indicative of scurvy, which is caused by a lack of vitamin C.
117
What are the symptoms of dumping syndrome?
Rapid gastric emptying, maldigestion of macromolecules, osmotic diarrhea
## Footnote
Dumping syndrome occurs after procedures like duodenal bypass.
118
What laboratory assay should be performed if a patient develops antibodies against FVIII replacement therapy?
Assay for FVIII inhibitory antibodies
## Footnote
This is crucial to manage hemophilia treatments effectively.
119
What condition is indicated by the introduction of fruit and vegetables into an infant's diet causing diarrhea?
Sucrase deficiency
## Footnote
A negative reducing sugar test is expected in this case.
120
What are the two most common causes of a clotting disorder indicated by recurrent bleeding?
von Willebrand disease (vWD), Factor VIII deficiency
## Footnote
Both conditions present with a normal PT and abnormal PTT.
121
What toxin does Vibrio cholerae secrete that leads to secretory diarrhea?
A toxin that activates the alpha subunit of Gs-proteins
## Footnote
This increases cAMP levels and causes chloride efflux.
122
What vitamin is essential for the folding of collagen into its triple helical conformation?
Vitamin C
## Footnote
It acts as a cofactor for prolyl and lysyl hydroxylases.
123
What dietary change may lead to changes in prothrombin times in a patient on warfarin?
Reintroduction of vitamin K-rich foods
## Footnote
Dark green vegetables are high in vitamin K.
124
What condition is indicated by high ACTH levels along with physical findings of Cushing syndrome?
Hypercortisolism
## Footnote
This leads to symptoms such as muscle weakness due to increased gluconeogenesis.
125
What causes sudden adrenal insufficiency in a patient with a history of steroid use?
Long-term suppression of adrenal function
## Footnote
This occurs due to abrupt cessation of corticosteroids.
126
What does high methylmalonic acid indicate in a patient with macrocytic anemia?
Vitamin B12 deficiency
## Footnote
Methylmalonic CoA mutase requires vitamin B12 as a cofactor.
127
What is disturbed after bariatric gastric bypass surgery affecting vitamin B12 absorption?
Gastric secretions and intrinsic factor production
## Footnote
This impacts the release and absorption of vitamin B12.
128
What vitamin deficiency results in increased PT and PTT due to low levels of coagulation factors?
Vitamin K deficiency
## Footnote
Vitamin K is crucial for the synthesis of clotting factors in the liver.
129
What condition is indicated by symptoms in a breastfed newborn that suggest GALT deficiency?
Galactose-1-phosphate uridylyltransferase (GALT) deficiency
## Footnote
This leads to increased galactose and galactitol production.
130
What does von Willebrand disease primarily affect?
PTT only, not PT
## Footnote
von Willebrand factor (vWF) stabilizes factor VIII, and its deficiency leads to increased PTT due to low levels of factor VIII.
131
What condition is indicated by symptoms of galactose-1-phosphate uridylyltransferase (GALT) deficiency?
Cataracts, hepatomegaly, jaundice
## Footnote
GALT deficiency leads to increased galactose, which can be converted to galactitol causing cataracts.
132
What does increased PTT in von Willebrand disease indicate?
Destabilization of factor VIII
## Footnote
Absence of vWF affects platelet plug formation, increasing bleeding time.
133
What is orotic aciduria caused by?
Deficiency in UMP synthase
## Footnote
It leads to blockage in de novo pyrimidine synthesis and orotic acid accumulation in urine.
134
What are the symptoms of kwashiorkor?
Weight loss, edema
## Footnote
It results from protein-energy malnutrition.
135
True or False: Increasing pH due to respiratory alkalosis increases oxygen delivery to tissues.
False
## Footnote
Elevated pH increases oxygen binding to hemoglobin, which is undesirable in this context.
136
What autoimmune condition is characterized by atrophic gastritis?
Autoimmune-mediated atrophic gastritis
## Footnote
It typically affects the body of the stomach, leading to achlorhydria.
137
What does the presence of parietal cell antibodies indicate?
Autoimmune gastritis
## Footnote
It is associated with a low serum pepsinogen level.
138
What does the absence of Multidrug resistance protein 2 lead to?
Jaundice
## Footnote
It is essential for transporting bilirubin conjugated in the hepatocyte into bile canaliculi.
139
What is the most likely cause of jaundice in a newborn with breastfeeding difficulties?
Physiologic jaundice
## Footnote
It develops due to dehydration and fewer bowel movements.
140
What is pathologic jaundice characterized by?
Very rapid onset of severe jaundice after birth
## Footnote
Conditions such as biliary atresia or G6PD deficiency must be investigated.
141
What is the likely diagnosis for a child with chronic pancreatitis and failure to thrive?
Cystic fibrosis
## Footnote
It leads to abnormally thickened pancreatic secretions.
142
What does acute viral hepatitis present with?
Marked hepatocellular damage and clinical jaundice
## Footnote
Hepatitis A is the most likely diagnosis in endemic areas.
143
What enzyme is key to bilirubin transport across cell membranes?
Multidrug resistance protein 2
## Footnote
Its absence results in Dubin-Johnson syndrome.
144
What is the typical outcome of bilirubin in Gilbert syndrome?
Elevated unconjugated bilirubin
## Footnote
It is a benign condition.
145
What is the role of glutathione in oxidative stress?
Reduces oxidative stress
## Footnote
Glutathione levels are believed to be lower in kwashiorkor.
146
What is the result of a deficiency in UMP synthase?
Orotic aciduria
## Footnote
It blocks de novo pyrimidine synthesis, affecting rapidly dividing cells like red blood cells.
147
What condition is characterized by a defect in the H+/K+ ATPase pump?
Autoimmune-mediated atrophic gastritis
## Footnote
It leads to achlorhydria and formation of intrinsic factor antibodies.
148
What leads to the formation of pigment stones in sickle cell disease?
Chronic hemolysis and bilirubin precipitation
## Footnote
It obstructs the common bile duct.
149
What is a hallmark of kwashiorkor?
Hypoalbuminemia
## Footnote
It is due to protein-energy malnutrition.
150
What is the effect of hydroxyurea in sickle cell anemia?
Increases α-globin synthesis
## Footnote
It is not used for orotic aciduria.
151
What is the expected bilirubin level in acute viral hepatitis?
Often exceeds 2.0
## Footnote
This indicates significant hepatocellular damage.
152
Fill in the blank: The loss of intrinsic factor in autoimmune gastritis leads to the production of ______ antibodies.
Intrinsic factor
## Footnote
This is a marker of the disease.
153
What is the expected albumin and prothrombin time in acute hepatitis?
Normal
## Footnote
Exception may occur in rare cases of acute hepatic failure due to hepatitis A.
154
What happens to albumin levels in cirrhosis?
Markedly diminished
## Footnote
Albumin is synthesized exclusively in hepatocytes.
155
What is the most common micronutrient subject to depletion in bariatric surgery patients?
Vitamin B12
## Footnote
Copper deficiency is also a concern but less common.
156
What are the typical signs of vitamin B12 deficiency?
Smooth glassy tongue, positive Romberg test, abnormal gait, paresthesia
## Footnote
These neurological findings suggest B12 deficiency.
157
What laboratory findings indicate iron deficiency?
Increased total iron binding capacity (TIBC), decreased ferritin levels
## Footnote
Classic presentation of iron deficiency anemia.
158
What is the characteristic finding in Wilson disease?
Increased copper deposition in the cornea (Kaiser-Fleischer ring)
## Footnote
Typically presents in the second or third decade of life.
159
What does a cholestatic pattern in liver function tests indicate?
Iron overload, likely hemochromatosis
## Footnote
Characterized by unregulated iron absorption due to low hepcidin.
160
What is the primary cause of prolonged neonatal jaundice in hemolytic anemia?
Hemolysis
## Footnote
Could be due to pyruvate kinase or G6PD deficiency.
161
What triggers a sickle cell crisis?
Decreased availability of oxygen
## Footnote
Factors include low pH, increased temperature, and reduced oxygen.
162
What is the effect of high altitude on sickle cell hemoglobin?
Triggers sickling of red blood cells
## Footnote
Decreased oxygen availability promotes the T state of hemoglobin.
163
What is the folate trap phenomenon?
Inhibition of conversion of methyltetrahydrofolate to tetrahydrofolate due to lack of vitamin B12
## Footnote
Leads to accumulation of methyltetrahydrofolate.
164
What is characteristic of fatty acid oxidation disorders?
Nonketotic hypoglycemic episodes after fasting
## Footnote
Indicates inability to utilize fatty acids for energy.
165
What is the role of glutathione in red blood cells?
Neutralizes oxidative stress
## Footnote
G6PD deficiency leads to inadequate levels of reduced glutathione.
166
What are Heinz bodies?
Precipitated hemoglobin polymers due to oxidative stress
## Footnote
Formed in red blood cells under oxidative stress conditions.
167
What is the significance of elevated ferritin in hemochromatosis?
Indicates iron overload
## Footnote
Ferritin stores excess iron to protect against free iron damage.
168
What causes the accumulation of unconjugated bilirubin in hemolytic anemia?
Overwhelming hemolysis saturating hepatic conjugation
## Footnote
Results in increased indirect bilirubin levels.
169
What is the expected change in reticulocyte levels in hemolytic anemia?
Increased reticulocytes
## Footnote
Indicates the bone marrow's response to anemia.
170
In the context of a sickle cell crisis, what does increased 2,3-BPG do?
Favors the T state of hemoglobin
## Footnote
Increased sickling occurs as a result.
171
What is the relationship between Wernicke encephalopathy and thiamine deficiency?
Thiamine deficiency due to alcoholism and malnutrition
## Footnote
Requires glucose administration after thiamine for energy.
172
What is the effect of primaquine in G6PD deficiency?
Leads to hemolytic crisis and jaundice
## Footnote
Causes oxidative stress on red blood cells.
173
What does the presence of blood in the stool and abdominal tenderness suggest?
Inflammatory disorder in the colon
## Footnote
Symptoms indicate possible inflammatory bowel disease.
174
What is the significance of antitissue transglutaminase antibodies (tTG) in celiac disease?
tTG antibodies have the best specificity and sensitivity for screening celiac disease, especially in individuals with a first-degree relative diagnosed with the condition.
## Footnote
tTG antibodies can indicate adherence to a gluten-free diet; if levels rise, it suggests dietary indiscretion.
175
What is the typical presentation of fetal alcohol syndrome (FASD)?
Classic features include failure to thrive and facial dysmorphic features such as a thin upper lip, smooth philtrum, and small eye openings.
## Footnote
FASD is linked to maternal alcohol consumption during pregnancy.
176
What does a small bowel biopsy indicate in celiac disease diagnosis?
It is usually necessary only when establishing the diagnosis in the index case and may show flattened villi and deepened crypts.
## Footnote
This mucosal pathology can also be seen in other malabsorption disorders.
177
What is the cause of neurotoxicity in phenylketonuria (PKU)?
Excess phenylalanine crosses the blood-brain barrier, leading to neurotoxicity.
## Footnote
This condition is due to a deficiency in the enzyme phenylalanine hydroxylase.
178
What is the initial step in managing suspected malabsorption in patients?
An empirical trial of dietary restriction is the first step to identify potential dietary indiscretion.
## Footnote
If symptoms persist, further testing such as serologies for celiac disease may be warranted.
179
What are the symptoms associated with propionic acidemia?
Lethargy, muscle weakness, hypoglycemia, acidosis, and amino acids in urine support the diagnosis.
## Footnote
This condition is characterized by metabolic derangements due to enzyme deficiencies.
180
What is the classic presentation of Gaucher disease?
Bone pain, pancytopenia, and hepatosplenomegaly are classic presentations of this autosomal recessive disease.
## Footnote
Gaucher disease is caused by a defect in glucocerebrosidase.
181
What findings support a diagnosis of Tay-Sachs disease?
Cherry-red spot on the macula, onion skin lysosomes, and progressive developmental delay and loss of motor skills.
## Footnote
Tay-Sachs is due to a deficiency in beta-hexosaminidase A.
182
In pyruvate kinase deficiency, what is the consequence of impaired ATP generation?
There is irreversible membrane injury to red blood cells leading to chronic hemolytic anemia.
## Footnote
This results in elevated bilirubin levels and potential gallstone formation.
183
What does a deficiency of UMPS cause?
It leads to anemia and orotic aciduria, with crystals of orotic acid accumulating in the body.
## Footnote
This condition is characterized by refractory megaloblastic anemia to vitamin B12 and folate supplementation.
184
What is the role of mitochondrial disease in genetic disorders?
Mitochondrial disease is caused by mutations in mitochondrial DNA affecting energy metabolism, which can lead to various symptoms depending on the tissues affected.
## Footnote
Mitochondria have their own genome and are inherited maternally.
185
What is the hallmark of classical phenylketonuria?
Deficiency of phenylalanine hydroxylase leads to elevated levels of phenylalanine.
## Footnote
This condition requires dietary management to prevent neurotoxic effects.
186
True or False: The presence of hyperammonemia rules out lysosomal storage disorders.
True.
## Footnote
Hyperammonemia is typically not a feature of lysosomal storage disorders.
187
Fill in the blank: The enzyme deficiency in classic PKU is __________.
phenylalanine hydroxylase.
188
What is the consequence of a deficiency in muscle phosphofructokinase (PFK)?
It leads to exercise intolerance and increased bilirubin due to hemolysis.
## Footnote
This condition is also known as Tarui disease.
189
What is the primary function of the enzyme galactose-1-phosphate uridylyltransferase (GALT)?
It is involved in the metabolism of galactose and its deficiency causes galactosemia.
## Footnote
Symptoms include jaundice, failure to thrive, and cataracts.
190
What is cogen storage disorder?
A rare muscular metabolic disorder that does not lead to hemolytic anemia or gallstones.
191
What deficiency causes anemia and orotic aciduria in children?
Deficiency of UMPS.
192
What crystals are produced due to the accumulation of excess orotic acid?
Orotic acid crystals.
193
What symptoms indicate a failure to thrive and refractory megaloblastic anemia?
Clues in the case of UMPS deficiency.
194
Which deficiency leads to jaundice, hepatomegaly, and cataract?
GALT deficiency.
195
What does OTC refer to?
A urea cycle disorder.
196
What happens to ammonia levels in OTC deficiency?
Ammonia level would be elevated, and BUN would be low.
197
What causes orotic acid crystalluria in urea cycle disorders?
Increasing concentrations of ornithine and decreased citrulline.
198
What enzyme is deficient in Lesch-Nyhan syndrome?
HGPRT.
199
What are the symptoms of Wernicke-Korsakoff syndrome?
Dysmorphic features, hepatomegaly, profound hypotonia.
200
What is the best initial test for thyroid function?
Measure thyroid-stimulating hormone (TSH) in the blood.
201
What indicates primary hypothyroidism?
High TSH level.
202
What is the confirmatory test for hypothyroidism after TSH?
Free thyroxine (FT4) levels.
203
What is a sign of Graves disease?
Positive antithyroid peroxidase antibody.
204
What vitamin is used to treat Wernicke-Korsakoff syndrome?
Thiamine (vitamin B1).
205
What is the role of transketolase?
Transfers 2-carbon moiety in the hexose monophosphate pathway.
206
What condition is indicated by a negative tTG antibody in a patient with suspected celiac disease?
IgA deficiency.
207
What antibody is used to confirm celiac disease?
Tissue transglutaminase antibody.
208
What are the gluten-containing grains?
* Wheat
* Barley
* Rye
209
What characterizes Zellweger syndrome?
Dysmorphic facial features, hepatomegaly, profound hypotonia.
210
What enzyme is defective in phenylketonuria?
Phenylalanine hydroxylase.
211
What distinguishes Krabbe disease?
Optic atrophy leading to blindness.
212
What causes congenital chloride diarrhea?
Defective intestinal absorption of Cl− and secretion of HCO3−.
213
What electrolyte imbalances occur in congenital chloride diarrhea?
* Hypochloremia
* Hypokalemia
* Hyponatremia
* Metabolic alkalosis
214
What is Zollinger-Ellison syndrome associated with?
Elevated gastrin levels and recurrent ulcer disease.
215
What is the first-line therapy for decreasing uric acid levels in gout?
Allopurinol.
216
What does glucose 6-phosphatase deficiency lead to?
Gout due to accumulation of uric acid.
217
What is the effect of allopurinol on uric acid levels?
Decreases uric acid levels.
218
What is the primary cause of gout in this patient?
Decrease in HGPRT activity.
219
What is the clinical finding in glucose 6-phosphatase deficiency?
Fat cheeks, thin extremities, protuberant abdomen.
220
What is the role of AMP deaminase in glucose-6-phosphatase deficiency?
Stimulated by decreased inorganic phosphate concentration.
221
What can lead to a false-negative result in celiac disease serology?
IgA deficiency.
222
What dietary component should be avoided in lactose intolerance?
Milk.
223
What dietary component can cause diarrhea but is not watery?
Excess fiber.
224
What is the importance of PRPP in purine synthesis?
High levels accelerate purine biosynthesis.
225
What type of anemia is caused by folate deficiency?
Macrocytic anemia
## Footnote
Folate deficiency leads to larger red blood cells due to impaired DNA synthesis.
226
What condition is characterized by abdominal pain and microcytosis?
Acute porphyria
## Footnote
Acute porphyria can present with abdominal pain but does not cause gray tinged mucosa.
227
What is the primary cause of primary hypothyroidism in adults?
Hashimoto thyroiditis
## Footnote
Elevated TSH levels indicate primary thyroid gland failure.
228
What does a low BUN with elevated ammonia levels suggest?
Urea cycle disorder
## Footnote
This combination indicates a potential metabolic disorder affecting ammonia detoxification.
229
What is phenylketonuria (PKU)?
An autosomal recessive disorder resulting in low levels of phenylalanine hydroxylase
## Footnote
PKU leads to accumulation of phenylalanine, which can cause brain damage.
230
What is the pharmacologic treatment of choice for methanol poisoning?
Fomepizole
## Footnote
Fomepizole inhibits alcohol dehydrogenase, preventing the formation of formic acid.
231
What are the characteristic features of Zellweger syndrome?
Dysmorphic facial features, hepatomegaly, profound hypotonia
## Footnote
Zellweger syndrome is due to the loss of peroxisomes and accumulation of very long-chain fatty acids.
232
What are the symptoms of acute intermittent porphyria (AIP)?
Reddish urine, abdominal pain, neurological symptoms
## Footnote
AIP is triggered by factors like ethanol and involves the accumulation of porphobilinogen.
233
Fill in the blank: A deficiency in branched-chain keto acid dehydrogenase causes _______.
Maple syrup disease
## Footnote
This condition is characterized by elevated branched-chain amino acids and a distinctive urine odor.
234
What vitamin is essential for recycling homocysteine to methionine?
Vitamin B12
## Footnote
Vitamin B12 is a cofactor for methionine synthase, crucial in this metabolic pathway.
235
What does orotic aciduria indicate?
Deficiency of UMPS
## Footnote
It leads to the accumulation of orotic acid and is associated with megaloblastic anemia.
236
What is the primary treatment for hereditary fructose intolerance?
Diet elimination of fructose, sorbitol, and sucrose
## Footnote
Avoiding these sugars prevents symptoms and complications.
237
True or False: Thiazide diuretics can increase uric acid levels and predispose to gout.
True
## Footnote
Thiazides increase uric acid reabsorption, which can lead to gout attacks.
238
What condition is characterized by very long-chain fatty acid accumulation?
Zellweger syndrome
## Footnote
This condition results from a complete loss of peroxisomes.
239
What is the initial step in managing a patient with suspected septic arthritis?
Arthrocentesis
## Footnote
This procedure allows for fluid analysis to determine the nature of the joint condition.
240
What does a deficiency in cystathionine beta synthase lead to?
Homocystinuria
## Footnote
This condition is characterized by elevated homocysteine levels and various systemic effects.
241
What is the significance of elevated serum ammonia levels?
Possible urea cycle disorder
## Footnote
Elevated ammonia can indicate impaired ammonia detoxification, leading to encephalopathy.
242
Fill in the blank: The symptoms of metabolic acidosis, hypoglycemia, and hyperuricemia can indicate _______.
Hereditary fructose intolerance
## Footnote
These symptoms are associated with deficiencies in fructose metabolism.
243
What distinguishes gout from pseudogout?
Crystal shape in joint aspirate
## Footnote
Gout shows needle-shaped crystals, while pseudogout exhibits rhomboid-shaped crystals.
244
What are the primary symptoms of Lesch-Nyhan disease?
Spastic muscle movement, gouty arthritis, self-mutilation, neurologic impairment
## Footnote
Lesch-Nyhan disease is a genetic disorder that affects purine metabolism.
245
What is the consequence of fructokinase deficiency?
Elevated fructose levels in blood and urine without significant symptoms
## Footnote
Fructokinase deficiency is a rare genetic disorder that affects fructose metabolism.
246
What should be performed first in the case of suspected joint infection?
Arthrocentesis
## Footnote
This procedure involves withdrawing joint fluid for analysis.
247
What tests should be sent after performing arthrocentesis?
Gram stain, culture, crystal analysis, white blood cell count
## Footnote
These tests help diagnose the cause of joint effusion.
248
True or False: Increased NADH from alcohol metabolism inhibits gluconeogenesis.
True
## Footnote
Increased NADH blocks substrates from entering the gluconeogenesis pathway.
249
What metabolic change occurs after glucose administration in emergency situations?
Increase in fatty acid synthesis
## Footnote
This occurs due to excess NADH shunting glucose derivatives towards fat synthesis.
250
What condition is indicated by elevated porphobilinogen deaminase?
Acute intermittent porphyria (AIP)
## Footnote
The 4Ms (maladies, menstruation, medication, malnutrition) can trigger AIP attacks.
251
What is the characteristic symptom of ethylene glycol toxicity?
Sweet taste and presence of calcium oxalate crystals in urine
## Footnote
Ethylene glycol is commonly found in antifreeze and can cause severe metabolic acidosis.
252
What is the cause of metabolic acidosis in diabetic ketoacidosis?
Increased degradation of triacylglycerols and fatty acids
## Footnote
This occurs due to an imbalance in insulin and glucagon levels.
253
What distinguishes nonalcoholic steatohepatitis (NASH) from other liver diseases?
Increased AST/ALT levels indicating inflammatory response in the liver
## Footnote
NASH is related to metabolic syndrome and can lead to liver fibrosis.
254
Where does plaque formation begin in atherosclerosis?
At the site of initial injury of the intima of the vessel wall
## Footnote
This injury leads to leukocyte infiltration and increased permeability.
255
What is the impact of adiponectin in patients with NASH?
Decreased levels lead to increased TAGs in hepatocytes
## Footnote
This results in fat deposition and inflammation in the liver.
256
What role do advanced glycation end products (AGE) play in diabetes?
Disrupt normal protein function, contributing to complications like neuropathy and retinopathy
## Footnote
AGE formation is a result of prolonged high blood glucose levels.
257
What are the symptoms of acute cholecystitis?
Pain due to gallstone obstruction of the cystic duct
## Footnote
Symptoms typically include right upper quadrant pain, especially after meals.
258
What is the relationship between metabolic syndrome and gallstones?
Patients with metabolic syndrome have a higher risk of developing gallstones
## Footnote
Factors like obesity and insulin resistance contribute to gallstone formation.
259
What is the effect of exercise on glucose uptake in muscles?
Exercise activates AMPK, increasing GLUT4 translocation to the cell membrane
## Footnote
This enhances glucose uptake from circulation.
260
What is the importance of measuring plasma potassium levels in diabetic patients?
It must be measured empirically due to cellular shifts during acidosis
## Footnote
Hydrogen ions enter cells, exchanging with potassium, leading to a net loss of potassium.
261
What are the symptoms indicating cholelithiasis causing cholecystitis?
Duration and location of pain, association with large meals, and vomiting
262
What laboratory findings suggest a healthy liver?
AST/ALT, albumin, and PT/INR within normal range
263
Is hypercholesterolemia a sufficient explanation for the patient's symptoms?
No
264
What must lipase and amylase levels be to establish a diagnosis of pancreatitis?
At least three times the normal value
265
What does a family history and laboratory findings with normal PT and prolonged PTT imply?
Hemophilia A
266
What type of disorder is hemophilia A?
X-linked recessive disorder
267
What causes hemophilia A?
Deficiency in factor VIII
268
What are the coagulation factors in the extrinsic pathway?
* Tissue factor (factor III) * Factor VII
269
What leads to prolonged PT time?
A defect in the extrinsic pathway
270
What do common pathway disorders lead to?
Increased PT and PTT
271
What are the coagulation factors in the common pathway?
* Factor X * Factor V * Factor II * Factor I
272
Does platelet plug formation change PT or PTT?
No
273
What is the cause of obstructive jaundice in this case?
Pancreatic tumor
274
What happens to unconjugated (indirect) bilirubin in obstructive jaundice?
No change
275
What causes an increase in direct (conjugated) bilirubin?
Backflow into circulation due to biliary tract obstruction
276
What happens to feces color in obstructive jaundice?
Light-colored feces due to reduction in stercobilin
277
What happens to urobilinogen in obstructive jaundice?
Less urobilinogen gets into circulation and urine
278
True or False: A defect in GPIb, GPIIb/IIIa, or autoantibodies against GPIIb/IIIa changes PT or PTT.
False
