Chromosomal Abnormalities

Question 1

Mass on neck, edema, bicuspid aortic valve, streak ovaries w/ amenorrhea and infertility, webbed neck, widely spaced nipples.

Answer 1

Turner Syndrome. Mass=cystic hygroma. Edema is due to coarctation of the aorta.
45 X,O due to loss of paternal chromosome X.

Question 2

Cardiac defects, clenched fists, rocker bottom feet, omphalocele, low-set ears.

Answer 2

Edward Syndrome (Trisomy 18), caused by meiotic nondisjunction.

Question 3

Round face, cat-like cry, microcephaly.

Answer 3

Cri-du-chat (cry like a cat) syndrome, due to short arm de novo deletion of 5th chromosome (5p)

Question 4

Flat face, Oblique palpebral fissures, epicanthic folds, ASD, sometimes cystic hygroma, only one crease on palm.

Answer 4

Down Syndrome.

Can be due to meiotic nondisjunction or Robertsonian translocation

Question 5

What is the name of Trisomy 13? What are the clinical features?

Answer 5

Patau Syndrome (due to nondisjunction of aging moms)
Cleft Palata, punch out lesions in scalp, omphalocele, microcephaly, polydactly.
The problem is that there wasn't correct prechordal mesoderm fusion, results in midline defects.