Clinical Vignettes Flashcards
What are the chromosomal abnormalities associated with Down Syndrome?
Trisomy 21
How do you test for the chromosomal abnormalities associated with Down Syndrome?
Quad screen in early 2nd Trimester can identify risk for having a baby with trisomyWoman may be offered a procedure to determine karyotype (amniocentesis) performed at 16 weeks.High risk women may be offered chorionic villus sampling (VS) at 11-12 weeks.
What is a major risk factor for having a baby with Down Syndrome?
Advanced Maternal Age (>35)
What are the two chemical mechanisms for testing for trisomy?
Karyotyping (count 47 chromosomes)FISH testing: faster results
What are the physical features (phenotypes) associated with Down Syndrome?
Normal growth parameters, brachecephaly, mid face hypoplasia, up-slanting palpebral fissures, epicanthal folds, Brushfield spots, dysplastic small pinnae, heart murmur may be present, genitalia may be abnormal, especially in males (undescended testicles, small phallus, hypospadias), incurving 5th finger, small digits, increased space b/w 1st and 2nd toes, increased joint range of motion, diffuse hypotonia.
What are the most serious (requiring surgery) medical problems seen in Down syndrome?
Congenital heart disease (1/3-1/2 of babies). Endocardial cushion defect, which is also called atrioventricular canal (AVC).GI tract defects: 10-15% of babies with DS. Esophageal or duodenal atresias, which leads to polyhydramnios during pregnancy.Both require surgical repair.
What are some other medical issues common in patients with Down Syndrome?
Small tear ducts, small eustachion tubes, small airway, eye problems (stabismus, nysatmus, cataracts, myopia), ear problems (infections, hearing loss), thyroid problems, celiac disease, diabetes, feeding issues, GERD, constipation, intellectual disabilities, autism, depression, Alzheimers.
What is the developmental and behavioral phenotype of those with Down Syndrome?
Decreased IQ, Intellectual disabilities. Increased incidence of depression.
What are the chromosome 15 abnormalities associated with Prader-Willi Syndrome?
A deletion of 15q11-q13 from the paternal allele. Or, there could be maternal disomy.
How do you test for the chromosomal abnormalities associated with Prader-Willi Syndrome?
FISH testing can confirm the deletion.Methylation testing can also help identify PWS.
What is the role of imprinting disorders involving chromosome 15?
It is critical for the information from the maternal and the paternal allele to be present in order for the baby to be normal. The region of chromosome 15 that is important is imprinted (methylated). If there is an imprinting error, the chromosomes will be marked incorrectly, resulting in either Prader-Willi or Angelman syndrome.
What are the physical features (phenotypes) of those with Prader-Willi syndrome?
Infant: floppy child, undescended testicles, lighter pigmentation, almond shaped eyes, severe feeding problems.Toddlers: feeding becomes voracious, obesity, strabismus, nysagmus
What are the medical problems seen in patients with PWS?
Eye problems (strabismus, nystagmus), scoliosis, obstructive sleep apnea (contraindication to the use of growth hormone), obesity.
What is the developmental and behavioral phenotype of those with PWS?
Mild-moderate cognitive disabilities are usually found, behavioral issues are common.
Recognize the clinical presentation of patients with Turner Syndrome
Eye: Inner canthal folds, blue sclerae, ptosisEar, nose: Prominent Auricles, low-set, high narrow mouth palate; small mandibleNeck: Low posterior hairline, webbingChest: Broad widely spaced Nipples; pectus excavatumSkeleton: Cubitus valgus, short fourth metacarpal and/or metatarsal, madelung deformity, scoliosis
Enumerate challenges across the lifespan in patients with Turner Syndrome
Has trouble with math, is short, late development of sexual characteristics, infertility, concerns regarding health and aging.
Recognize the clinical challenges related to patients with Turner Syndrome
Secret keepingDifficulty communicating an infertility diagnosisPerceived negative experiences with physicians
What is thalassemia?
Thalassemia is a disorder with imbalanced globin synthesis leading to defective hemoglobin production leading to destruction of red blood cell precursors in the bone marrow.
What is the diagnosis of thalassemia based on?What is the differential diagnosis?
Diagnosis is based on:Presence or absence of hepatosplenomegalyCBC and reticulocyte countNBS (Newborn screen)Hemoglobin electrophoresisDifferential diagnosis:Iron deficiency anemiaLead poisoningAnemia of chronic disease
What is the incidence of thalassemia?
269 million carriers in the world, higher in Africans, SE Asians, and Mediterraineans350,000 babies born throughout the world each year with major hemoglobin disorders. Most die under-diagnosed, untreated, or under-treated.
What is the genetic basis of thalassemia?
Several mutations and deficiencies in hemoglobin units.
What is the treatment of thalassemias?
β Thalassemia major: Chronic transfusion, treatment of complications (eg: iron overload), Bone Marrow transplantβ Thalassemia trait / αThalassemia 1 or 2 gene deletion: No treatmentα Thalassemia 3 gene deletion (Hgb H disease): Occasional transfusion of PRBCs, Splenectomy
Explain causes and risk factors of thrombocytopenia.
Diverse reasons for this.Decresed production or increased destruction of platelets. Hepatosplenomegaly can contribute to this. Spleen is clearing house for used up blood cells. When you have hepatosplenomegaly, spleen gets giant. By occupying more space, it acts like a big sponge. Physical expansion of spleen reduces platelet concentration in blood.
Explain causes and risk factors of hepatosplenomegaly.
Infectious diseases, cirrhosis, cancer, vascular and organ failure, blood disorders. Spleen cycles all blood cells, liver is involved in metabolic diseases, which Gaucher’s is. Macrophages end up being stored in liver and spleen once this disease is initiated.
