Genetics

Question 1

Which is not included in the Hall’s criteria in diagnosis down syndrome?
(ch 98 table 98.4 p 660)

A. Hypotonia
B. Upward slanted palpebral fissures
C. Single transverse palmar creases
D. Protruding tongue

Answer 1

D. Protruding tongue

Question 2

Full mutation in Fragile X syndrome is considered as having ___ number of repeats in CGG triplet.

A. 5-40
B. 59-100
C. 100-200
D. >200

Answer 2

D. >200

Question 3

A 36 y/o primigravid at 8 weeks of gestation was referred to you for genetic counseling.. The mother said that her husband’s sister had a child with unusual facies died at 6 mos old because of a congenital heart defect. What would youbadvise the mother?

A. Abort the pregnancy because she is considered at high-risk for a newborn with severe complications of Down syndrome.
B. Offer screening for down syndrome
C. Request karyotyping upon delivery of the newborn
D. Wait until the 3rd trimester before performing screening for possible Down syndrome

Answer 3

B. Offer screening for down syndrome

Question 4

Which is not part of the screening tests for Down syndrome during the first trimester?

A. Inhibin
B. Nuchal. Translucency
C. Maternal serum B hcg
D. Pregnamcy-associated plasma protein A (PAPP-A)

Answer 4

A. Inhibin

Question 5

The quad screen are recommended tests for scree ing Down syndrome in the second trimester. Which of the following is not part of the quad screen?

A. PAPP-A
B. Free B hcg
C. Unconjugated estradiol
D. Maternal serum AFP

Answer 5

A. PAPP-A

Question 6

This finding is univeral in Down syndrome.
(ch98 p 659)

A. Developmental delay
B. Congenital heart defect
C. Hypothyroidism
D. Congenital hearing loss

Answer 6

A. Developmental delay

Question 7

Most common and clinicallybsignificant type of human chromosomal abnormality
(ch 98 p658)

A. Polyploidy
B. Aneuploidy
C. Diploidy
D. Triploidy

Answer 7

B. Aneuploidy

Question 8

A 17 yr old female was brought in the OPD due to absence of menses. On physical exam, she has a low posterior hairline, flat chest, webbed neck and gr 2/6 systolic murmur on the 5th ICS LMCL. Height for age is below - 2 SD, BMI at +1 SD. Which of the following is true?
(ch 98 p 669)

A. She should be treated with growth hormone
B. Maternal age at the time of conception is a major predisposing factor in this condition
C. More than half of affected patients will have below average intelligence
D. In 75% of cases, the lost sex chromosome is of maternal origin.

Answer 8

A. She should be treated with growth hormone

*turner syndrome (:

Question 9

Patients with turner syndrome at at risk of what type of neoplasm?

A. Choriocarcinoma
B. Rhabdomyosarcoma
C. Gonadoblastoma
D. Teratoma

Answer 9

C. Gonadoblastoma

Question 10

Which is true of Noonan syndrome?
(ch 98 p669)

A. It affects only males
B. Noonan syndrome typically involves left-sided congenital heart lesions
C. Short stature is not common
D. It is an autosomal dominant disorder

Answer 10

D. It is an autosomal dominant disorder

Question 11

The following statements are true regarding klinefelter syndrome except?
(ch 98 p669)

A. They have stunted growth
B. The aneuploidy of the sex chromosome is due to errors in paternal non disjunction.
C. The greater the aneuploidy, the more severe the mental impairment and dysmorphism.
D. There is 50% chance of having gynecomastia

Answer 11

A. They have stunted growth

Question 12

True of fragile x syndrome except:

A. FMRP gene is silenced by multiple CGG repeats
B. Males with premutation triple repeat expansion has > 200 copies if CGG and is associated with more severe ID
C. Females with premutation triple repeat expansions are at risk for premature ovarian failure
D. Diagnosis is possible by DNA testing

Answer 12

B. Males with premutation triple repeat expansion has > 200 copies if CGG and is associated with more severe ID

Question 13

Autosomal dominant inheritance
(ch 97 p641)

A. Shows a vertical transmission pattern and can appear in multiple generations
B. Affects females more than males
C. Usually seen in families with consangineous parents
D. Shows horizontal transmission of multiple affected members in a kindred of the same generation, but no affected family in other generations

Answer 13

A. Shows a vertical transmission pattern and can appear in multiple generations

Question 14

True of autosommal recessive inheritance except:
(ch97 p 642)

A. Shows a vertical transmission pattern and can appear in multiple generations
B. Recurrence risk is 25% for carrier parents who have had a previously affected child
C. Usually seen in families with consangineous parents
D. Shows horizontal transmission of multiple affected members in a kindred of the same generation, but no affected family in other generations

Answer 14

A. Shows a vertical transmission pattern and can appear in multiple generations

Question 15

Pp and Tt have a son, Bb. When Bb was born, he presented with jaundice on the 36th HOL, but was otherwise well. He was admitted for phototherapy which lasted for 2 days. His NBST came back positive for G6PD deficiency. He is now 2months old and was brought into your clinic with a positive confirmatory test for G6PD deficiency. Both parents denies history of thisndisorder in their respective familes. If they wish to conceive again, what are the chances of having another child with the same disorder?
(ch 97 p 645)

A. 25% chance of having an affected daughter
B. 25% chance of having a child that does not inherit the affected X-linked gene
C. 25% chance of having another son with the same disease
D. 50% chance of having another son with the same disease

Answer 15

C. 25% chance of having another son with the same disease