Diseases and Disorders Exam 4 Flashcards
(26 cards)
1
Q
Hereditary Fructose Intolerance
A
- deficiency of aldolase B
- leads to an accumulation of fructose 1-P in the liver and kidney
- sx first appear when baby is weaned from milk
- leads to inhibition of glycolysis, decreased hepatic ATP, inhibited gluconeogenesis, hypoglycemia, lactic acidosis
- remove fructose from diet to prevent liver failure and possible death
2
Q
Essential Fructosuria
A
- genetic deficiency in fructokinase KHK gene
- fructose can’t be converted to fructose 1-P
- fructose accumulates in the urine
- is benign
3
Q
Lactase Deficiency
A
- inability to digest lactose
- leads to watery diarrhea and gas
- can be genetic, age related or from injuries to the mucosa
- may have trouble digesting lactose after periods of severe food poisoning or diarrhea.
4
Q
Acarbose
A
- drug that blocks pancreatic alpha-amylase and brush-border alpha-glucosidases
- can be used to treat DM2 by reducing the rate at which ingested carbs reach the blood stream
- gas and diarrhea are common side effects so it is not used very often
5
Q
Mutations in SGLT1
A
malabsorption of glucose and galatose
6
Q
Mutations in SGLT2
A
familial renal glycosuria
7
Q
Inhibitors of SGLT2 (gliflozins)
A
- used to treat DM2
- SGLT2 can only reabsorb up to 200 mg/dl of glucose, over that it is peed out
- thus inhibiting SGLT2 will increase glucose excretion in the urine
8
Q
Neonatal Diabetes (MODY)
A
- mutation in KCNJ11 gene which codes for a subunit of the K-ATP channel
- leads to the channel being permanently open and prevents the release of insulin from pancreas
- can be treated with sulfonylureas which close the K channel
9
Q
GLUT1 Deficiency Syndrome
A
- decreased glucose transport into the CSF and the brain
- pts with seizures and developmental delays
10
Q
Lactic Acidosis
A
- Excess lactic acid in blood (>5mM) which decreases the pH (<7.2)
- Caused by increased NADH/NAD+ ratio which prevents pyruvate from entering the TCA cycle so it becomes lactate
- causes are excess alcohol, hypoxia, genetic
11
Q
Mercury and Arsenic Poisoning
A
- inhibit glyceraldehyde 3-P dehydrogenase
- mercury inactivates
- arsenite subs for Pi in rxn
- prevents glycolysis
12
Q
Deficiency of pyruvate kinase or phosphoglycerate kinase
A
- depletes cells of ATP
- osmotic balance is messed up
- RBCs swell and burst -> hemolytic anemia
13
Q
Hyperglycemia and Sorbitol
A
- in uncontrolled DM, lots of glucose enters the lens, retina, nerve and kidneys
- glucose is converted to sorbitol
- these cells lack sorbitol dehydrogenase to make fructose
- sorbitol accumulates, and causes cells to swell
14
Q
Galactokinase and GALT Deficiencies
A
- when galactose accumulates in cells, aldose reductase reduces it to galactitol
- this can lead to cataracts very early in life, vomiting and diarrhea after consuming galactose, liver damage and mental retardation
15
Q
G6PD Deficiency
A
- one of most common genetic diseases
- X linked
- usually only causes problems when under increased oxidative stress
- affected individuals show Heinz bodies in their RBCs which are clumps of denatured proteins
16
Q
Classes of G6PD Deficiency
A
- Class I: most severe, anemia even in absence of stress
- Class II (Mediterranean): severe, enzyme with reduced stability
- Class III (A): moderate, oldest cells have reduced enzyme activity and lyse
- Class IV: no clinical sx
17
Q
GSD 0
A
- Disorder name: n/a
- Enzyme: glycogen synthase
- Organ: liver
- Pathway: glycogenesis chain enlongation
- Manifestation: hypoglycemia, failure to thrive, early death
18
Q
GSD I
A
- Disorder name: von Gierke
- Enzyme: glucose 6-phosphatase
- Organ: liver
- Pathway: glycogenolysis/gluconeogenesis: dephosphorylation of glucose 6-P to glucose
- Manifestation: enlarged liver and kidney, growth failure, fasting hypoglycemia, acidosis, lipidemia, thrombocyte dysfunction
19
Q
GSD II
A
- Disorder name: Pompe
- Enzyme: acid maltase
- Organ: all with lysosomes
- Pathway: lysosomal glycogenolysis: release of Glc
- Manifestation: in infants - progressive muscle hypotonia, cardiac failure and death before age 2.
in juveniles - myopathy and variable cardiac involvment
in adults: muscular dystrophy like features, glycogen deposits with short outer branches
20
Q
GSD III
A
- Disorder name: Cori
- Enzyme: Debranching enzyme
- Organ: liver, skeletal muscle, heart
- Pathway: Glycogenolysis: Glc cleavage and release from branch point
- Manifestation: fasting hypoglycemia, hepatomegaly in infants and some myopathy. Glycogen deposits have short outer branches
21
Q
GSD IV
A
- Disorder name: Andersen
- Enzyme: Glucosyl (4:6) transferase (branching enzyme)
- Organ: liver
- Pathway: glycogenesis: chain branching
- Manifestation: hepatosplenomegaly, usually fatal
22
Q
GSD V
A
- Disorder name: McArdle
- Enzyme: muscle glycogen phosphorylase
- Organ: skeletal muscle
- Pathway: glycogenolysis: Glc 1-P release
- Manifestation: exercise induced muscle pain, cramps and progressive weakness
23
Q
GSD VI
A
- Disorder name: Hers
- Enzyme: liver glycogen phosphorylase
- Organ: liver
- Pathway: glycogenolysis: Glc 1-P release
- Manifestation: hepatomegaly, mild hypoglycemia, good prognosis
24
Q
GSD VII
A
- Disorder name: Tarui Syndrome
- Enzyme: PFK-1
- Organ: muscle, RBCs
- Manifestation: exercise induced muscle pain, cramps and progressive weakness, enzymopathic hemolysis
25
GSD XI
- Disorder name: Fanconi-Bickel Syndrome
- Enzyme: GLUT 2
- Organ: intestine, pancreas, kidney, liver
- Manifestation: glycogen accumulation in liver and kidney, rickets, growth retardation, glucosuria
26
Neonatal Hypoglycemia
- when newborn is cut off from mothers glucose, will become hypoglycemic and epi and glucagon will stimulate the liver to begin glycogenolysis.
- if newborn lacks glycogen stores can be life-threatening
- if mother had unontrolled DM, baby will have high glycogen stores and insulin levels. will not be stimulated by glucagon to begin glycogenolysis
