Genetics

Question 1

Disorders of chromosome no.

Answer 1

Down, Edward Patau Kleinfelter Turner

Question 2

Most common autosomal trisomy

Answer 2

trisomy 21 or Down Syndrome

Question 3

Antenatal signs of Down Syndrome

Answer 3

Nuchal thickening, flattened nose bridge

Question 4

Clinical signs of trisomy 21

Answer 4

Simian crease, Wide sandal gap, Flat occiput, incurved fifth finger

Question 5

Types of down syndrome

Answer 5

nondisjunction, mosaicism and translocation

Question 6

What is the most common of the cytogenetics assoc with down syndrome?

Answer 6

non disjunction where chromosome 21 pair fails to separate at meiosis, therefore one gamete has two C21 and the other has none therefore fertilization of the gamete that has two C21 chromosomes results in Trisomy 21

Question 7

What antenatal testing is done to detect trisomy 21?

Answer 7

FISH or rapid PCR testing. cell free dna is becoming part of routine testing

Question 8

The risk of having another child is three times more likely than the normal risk if you hada previous Down syndrome baby

Answer 8

True normally it is 1 in 650 but it would beome 1 in 200

Question 9

Robertsonian translocation is a part of what syndrome?

Answer 9

trisomy 21 and involves chromosomes 14 and 21

Question 10

Clinical signs of Edward syndrome

Answer 10

overlapping fingers and rockerbottom feet

Question 11

Patau Syndrome

Answer 11

Cleft lip and palate structural defect of brain

Question 12

Doudenal atresian and congenital heart disease are imediate complications of what trisomy?

Answer 12

21

Question 13

What are the clinical features of Turners 45 XO

Answer 13

lymphedema in neonates, short stature, webbed neck, ovarian dysgenesis, infertility, hypothyroidism, Coarction of the Aorta wide spaced nipples, renal anomalies recurrent otitis media

Question 14

9 yo boy, tall stature, small testes and gynaecomastia. What is the diagnosis?

Answer 14

Kleinfelter’s 47 xxy

Question 15

Cri du chat, di george and william syndrome are examples of what type of mutation?

Answer 15

deletions

Question 16

Charcot Marie tooth is what kind of genetic abnormality

Answer 16

defect in myelination, autosomal dom, mutation in pmp22 duplication. dysfunction in peripheral nervous system affecting hands and foot especially peroneal and tibial nerves pes cavus pes planus and hammer toe foot drop inverted champagne bottle appearance

Question 17

A 6-year-old boy is brought to your practice by his paternal grandmother for his first visit. She has recently received custody of him after his
mother entered the penal system in another state; she does not have much information about him. You note that the child is short for his age,
has downslanting palpebral fissures, ptosis, low-set and malformed ears, a broad and webbed neck, shield chest, and cryptorchidism. You hear a
systolic ejection murmur in the pulmonic region. His grandmother reports that he does well in regular classes, but has been diagnosed with
learning disabilities and receives speech therapy for language delay. His constellation of symptoms is suggestive of

Answer 17

noonan syndrome