Genetic disorder of childhood

Question 1

What is the role of the clinical genetician

Answer 1

Provide a diagnostic serve and genetic counselling for individuals or families with or at risk of conditions with a genetic basis

Question 2

What % of screening happens prenatally

Answer 2

70

Question 3

What is screened for post-natally

Answer 3

Cytogenetics of malignancy
Molecular testing for rare single gene disorders
Genetic risk factors

Question 4

What cytogenic testing happens prenatally

Answer 4

Karyotype

Aneuploidy

Question 5

What cytogenic testing happens postnatally

Answer 5

Solid tumours

Haematological malignancy

Question 6

What molecular testing happens prenatally

Answer 6

Sickle cell disease
Free feta DNA
Cystic fibrosis
Long tail

Question 7

What molecule testing happens postnatally

Answer 7

Fragile X
Cystic fibrosis
Breast cancer
Haemochromatosis
Factor V Leiden

Question 8

What is the function of a genetic marker

Answer 8

Tags a piece of DNA and can be used to track genes in families or populations

Question 9

Define SNP

Answer 9

Single nucleotide polymorphism
Variation in a single nucleotide that occurs at a specific position in the genome where each variation is present to some appreciable degree

Question 10

Define STR

Answer 10

Short tandem repeat

Question 11

When are genetic markers polymorphic

Answer 11

When frequency of minor allele in population is >1%

Question 12

What is genetic linkage

Answer 12

Tendency of DNA sequences that are close together on chromosome to be inherited together during meiosis

Question 13

The nearer the two genes on a chromosome…

Answer 13

The more likely they are to be inherited together

Question 14

How are positional candiates identified

Answer 14

Through genome wide genetic linkage analysis

Question 15

What can genetic markers be used to analyse in linkage analysis

Answer 15

Track the location of a disease

Question 16

How are functional candidates identified

Answer 16

Identified by functional association with previously identified disease genes

Question 17

How are exome/ genome sequencing identified

Answer 17

Identified as having rare variants in multiple unrelated affected individuals

Question 18

Define exome

Answer 18

All protein coding regions

Question 19

What % of the genome is exome

Answer 19

1.5

Question 20

What happens in exome sequencing

Answer 20

Comparing individual exome to the reference

Question 21

How are genetic variants classified on a scale of 1 to 5

Answer 21

1- Benign
2- Likely benign
3- Variant of unknown significance
4- likely pathogenic
5- pathogenic