chromosomal disorders in kids

Question 1

cri du chat: what abnormalities exist and what is the H&P

Answer 1

5p chromosome arm deletion

-high pitched ry, small head, intellectual disability, low birth weight, FTT

Question 2

wolf-hirschhorn: what abnormalities exist and what is the H&P

Answer 2

4p16 to end of arm. causes intellectual disability, cranial abnormalities, and seizures. “greek warrior helmet” face

Question 3

williams syndrome: what abnormalities exist and what is the H&P

Answer 3

elfin faces (short upturned nose, long philtrum, wide mouth), short stature, MR, cheerful/friendly personality, cardiac defects like supravalvular stenosis

Question 4

What are the manifestations of klinefelter syndrome?

Answer 4

47 XXY. males with testicular atrophy, tall think bodies, gynecomastia, infertility, possible intellectual disability, and psychosocial adjustment challenges

Question 5

What is the most common biochemical/cellular cause of trisomies?

Answer 5

nondisjunction during meiosis of maternal germ cells

Question 6

What are the key features of trisomy 18?

Answer 6

MR, small mouth, limb abnormalities, rocker bottom feet, overlapping fingers, cardiac problems, GI problems

Question 7

What are the key features of trisomy 13?

Answer 7

cleft lip and palate, cardiac problems, CNS defects, severe MR, round nose, polydactyly

Question 8

What are the expected labs/genetic testing of fragile x?

Answer 8

genetic screen shows hundreds of CGG repeats at the end of the x chromosome (# of repeats increase with each generation when inherited from a woman, but not from a man). prenatal DNA analysis may be done in woman with family hx