Structural And Numerical Chromosomal Abnormalities

Question 1

Wolf Hirschhorn syndrome-4p

Answer 1

STRUCTURAL

DELETION:loss of segment of chromosome

Question 2

Cri-du-chat syndrome 5p

Answer 2

STRUCTURAL

DELETION:loss of segment of chromosome

Question 3

Proximal part of long arm of 15 q absent
Paternally inherited
Name the syndrome ,type and type feature

Answer 3

Syndrome: (P)aternally inherited:(P)RADER-WILLI SYNDROME
STRUCTURAL
Microdeletion:deletion detected by high resolution banding

Question 4

Proximal part of long arm of 15 q absent
Maternally inherited
Name the syndrome ,type and type feature

Answer 4

Syndrome:ANGELMAN SYNDROME
STRUCTURAL ABNORMALITY
Microdeletion: deletion detected by high resolution banding

Question 5

Identify the abnormality category

Type:structural
Feature: exchange of segments between non homologous chromosomes

Clinical significance:may not always produce abnormal phenotype but can lead to formation of unbalanced gametes and carries high risk of abnormal progeny

Answer 5

ABNORMALITY:TRANSLOCATION

Question 6

Identify abnormality and type

Feature: Duplication of an entire arm of chromosome and deletion of the other chromosome arm

Answer 6

Type:STRUCTURAL
Abnormality: ISOCHROMOSOME

*Clinical significance: Duplication of genes

Question 7

Identify abnormality and type

Feature: Chromosome is deleted at both ends and deleted sticky ends adhere to each other in the form of a ring

Answer 7

Type:STRUCTURAL
Abnormality:RING CHROMOSOME

*CLINICAL SIGNIFICANCE:Clinical manifestations depend on deletion of the specific genes

Question 8

Down syndrome

State type, feature and category on basis of chromosomal type

Answer 8

Type:NUMERICAL
Feature:Trisomy,21
Category: autosomal

Question 9

Edward’s syndrome

State type, feature and category on basis of chromosomal type

Answer 9

Type: NUMERICAL
Feature:Trisomy,18
Category: autosomal

Question 10

Patau syndrome

State type, feature and category on basis of chromosomal type

Answer 10

Type: NUMERICAL
Feature:Trisomy,13
Category: Autosomal

Question 11

Turner’s syndrome

State type, feature and category on basis of chromosomal type

Answer 11

Type:NUMERICAL
Feature:45,XO
Category:Sex chromosomal
[Female phenotype]

Question 12

Klinefelter’s syndrome

State type, feature and category on basis of chromosomal type

Answer 12

Type:NUMERICAL
Feature:47,XXY
Category:sex chromosomal
[Male phenotype]