Genetics

Question 1

Autosomal Dominant Diseases

Answer 1

Achondroplasia, Huntington’s, Myotonic Dystrophy, Marfan’s, Neurofibromatosis, Von Willebrands

Question 2

Autosomal Recessive

Answer 2

CF, Sickle Cell, Tay Sachs, Alpha Thal, CAH, Almost ANY enzyme defect

Question 3

> 50% Sabs

Answer 3

Chromosomal disorders present in >50% first trimester sABs.
Most common Group: Trisomies T16
Most common Aneuploidy Monosomy X

Question 4

Recurrence Risk with prior aneuploiy

Answer 4

1%

Question 5

Chromosomal Disorder not assisated with increasing maternal age

Answer 5

monosomy X

Question 6

Advanced Paternal Age

Answer 6

AD Diseases

Question 7

Cri Du Chat

Answer 7

Deletion of 6p

Question 8

Most common cause of mental retardation in males

Answer 8

Fragile X

Question 9

Dx of B thal on Hb EP

Answer 9

Increased HbA2 and HbF

Question 10

Quad Screen analytes

Answer 10

AFP (fetal liver, most commonly abnl for wrong GA)
HCG
Estriol
Inhibin

Question 11

Quad Screen abnormalities for DS, NTD, T18

Answer 11

DS: Decreased AFP (sometimes increased HCG, decreased E3)
NTD: Elevated AFP
T18: All low

Question 12

Trisomy 18

Answer 12

Cardiac defect most common anatomic abnormality

Question 13

Trisomy 21

Answer 13

THickened nuchal fold most common

Others: shortened femur/humerus, hydronephrosis, duodenal atresia, cardiac defects, echogenic bowel