Genetic Evaluations

Question 1

indications for genetic evaluations

Answer 1

age greater than 35
hx of miscarriage/stillbirths
family hx of birth defects, mental retardation, growth retardation, neurologic conditions, familial cond.
fetal exposure to medications, intrauterine infections, radiation, toxic chemicals, illegal substance
ethic backgrounds

Question 2

phenotype

Answer 2

physical features

Question 3

genotype

Answer 3

diagnostic characteristics (labs)

Question 4

down syndrome (trisomy 21)

Answer 4

microcephaly, abnormal head shape
flattened nose
protruding tongue (due to hypotonia)
brushfield spots(small white, grayish, brown spots on iris)

Question 5

other manifestations seen with downs

Answer 5

seizures
congenital heart disease (VSD)
endocrine abnormalities
esophageal/ duodenal atresia
hearing/vision impairment
obesity
leukemia
early dementia (30-40 years old)

Question 6

Klinefelter’s syndrome (XXY syndrome)

Answer 6

only in males
extra X chromosome
presents in puberty
not inherited
most common cause of hypogonadism and infertility in men
tall statue
transverse crease
abnormal body proportions 
underdeveloped sexual characteristics
gynecomastia
learning disability

Question 7

Turner’s syndrome (XO syndrome)

Answer 7

only seen in females
most common sex-chromosome anomaly in females
puffy babies
most do not survive to term 
lymphedema
webbed neck
low hairline
learning disability
lack of secondary characteristics
"shield" shaped chest (widely spaced nipples)
HTN
coarctation of aorta (common)

Question 8

Marfan Syndrome

Answer 8

inherited connective tissue disorder affecting skeletal, cardiac, and ophthalmic body systems
tall stature
arm span exceeds height
thin extremities and fingers
long narrow face
pectus carinatum or excavatum
hyperextension of joints
kyphoscoliosis
high risk of having a aneurysm

Question 9

tay-sachs disease

Answer 9

found in ashkenazic jewish population
normal at birth; deterioration begins at 3-6 months
typical progression: decreased muscle tone, cherry red macula, listlessness, blindness, deafness, seizures, dementia, vegetative state, death

Question 10

Digeorge (Velocardiofacial) Syndrome

Answer 10

congenital defect of the parathyroid glands, thymus, and the conotruncal region of the heart
increased susceptibility to infections
abnormal facies
micrognathia (receding chin)
congential heart defects
significant neonatal morbidity and mortality associated with cardiac defects