Chromosome Abnormality Disorders ILA

Question 1

specific position of a gene on chromosome

Answer 1

locus

Question 2

specific version of a gene at the locus

Answer 2

allele

Question 3

chromosome number is not 46

Answer 3

heteroploid

Question 4

chromosomal number is nx23 (23,46,69…)

Answer 4

euploid

Question 5

any number of chromosomes

Answer 5

aneuploid

Question 6

viable trisomies

Answer 6

13, 18, 21, X

Question 7

extra X in females

Answer 7

XXX syndrome

Question 8

extra X in males

Answer 8

Klinefelter syndrome

Question 9

only viable monosomy

Answer 9

X chromosome

Question 10

2 acrocentric chromosomes that fuse near the centromere region with loss of the short arms; reciprocal

Answer 10

Robertsonian translocation

Question 11

most common robertsonian translocations

Answer 11

rob (13,14)
rob (14,21)

Question 12

joining of long arms of the same chromosome; usually X chromosomes

Answer 12

isochromosome

Question 13

most common chromosomal disorder; causes moderate intellectual disability

Answer 13

Down syndrome

Question 14

sx’s:
brachycephaly** (shortening of head anterior to posterior)
hypotonic at birth
risk of leukemia is 15 fold**

Answer 14

Down syndrome

Question 15

mainly caused by trisomy 21, but sometimes caused by rob (14,21)

Answer 15

Down syndrome

Question 16

cleft lip and palate*
microopthalmia
polydactyly*
dextrocardia
rarely inherited
rocker-bottom feet***

Answer 16

Patau Syndrome (Trisomy 13)

Question 17

dolichocephaly* (elongation of cranium)
clenched hands*
heart defects
respiratory problems
low survival rate (1%)***

Answer 17

Edward’s Syndrome (Trisomy 18)

Question 18

loss of X chromosome**
female
short and wide neck**
short stature**
swollen hands and feet
coarctation of aorta (narrowing)

Answer 18

Turner Syndrome (45, X)

Question 19

delayed milestones*
taller than ave.
reduced fertility
curving of pinky finger
epicanthal folds*
rarely diagnosed***

Answer 19

XXX Syndrome (47,XXX)

Question 20

in this syndrome, one copy of X is inactivated in females

Answer 20

XXX Syndrome

Question 21

extra X in male (can undergo inactivation)
hypogonadism
infertility
body disproportions

Answer 21

Klinefelter syndrome (47, XXY)

Question 22

“mewing cat”
deletion of short arm of chromosome 5
de novo deletion, but can be inherited from parent with balanced translocation
10% mortality

Answer 22

Cri du chat syndrome

Question 23

deletion on chromosome 7*
over-friendliness, anxiety*
flattened nasal bridge
problems with visual tasks***
hyperacusis
L hand and eye dominance

Answer 23

Williams Syndrome