Repro Genetics

Question 1

When are genetics included in repro medicine?

Answer 1

Pre-conception counselling
Early pregnancy screening
Down syndrome screening
Anomaly scan follow up
Neonatal screening

Question 2

When is targeted screening in pre-conception or early pregnancy done?

Answer 2

Family history - AD/ AR/ XL
Previous obstetric history
Population carrier screening - AR or XL

Question 3

What mutation causes sickle cell anaemia?

Answer 3

Mutation in haemoglobin gene - HbS
Sickle cell shape causes blockage of blood flow
Sickle cells are sticky

Question 4

What are the potential complications of sickle cell anaemia?

Answer 4

Stroke, cerebrovascular disease, retinopathy, hearing loss, balance problems, asthma, acute chest syndrome, sleep apnoea and pulmonary embolism

Question 5

Is sickle cell anaemia autosomal dominant or recessive?

Answer 5

Recessive

Question 6

What are the reproductive choices for inherited/ known diseases in family?

Answer 6

Early detection and treatment
Pre-implantation genetic diagnosis
Prenatal diagnosis
NIPD - non-invasive prenatal diagnosis
Gamete donation and adoption

Question 7

What done for the prenatal diagnosis?

Answer 7

Chorionic villus sampling

Question 8

What are the advantages of non-invasive prenatal testing/ diagnosis?

Answer 8

Excellent screening tests for trisomy 21, 18 and 13
Low false positive rate
Clarity of reported results

Question 9

What are the limitations of non-invasive prenatal testing/ diagnosis?

Answer 9

May be a false negative or no result
May be false positive with vanishing twin, maternal cancer, obesity or placental mosaicism
Cost of assay

Question 10

What are the investigations for abnormal scans?

Answer 10

Chromosomal microarray
Gene panel - skeletal dysplasia
Prenatal exome sequencing

Question 11

What is the positive of gene panel?

Answer 11

Quick and targeted interpretation

Question 12

What is the negatives of prenatal exome sequencing?

Answer 12

Interpretation has to be phenotypically driven
Slower and more expensive

Question 13

What does the new born bloodspot screening test for?

Answer 13

Sickle cell disease, CF, congenital hypothyroidism, phenylketonuria, medium-chain acyl-CoA dehydrogenase deficiency, maple syrup urine disease, isovaleric acidaemia, glutaric aciduria type 1 and homocystinuria

Question 14

What is the investigations for a seriously ill neonate?

Answer 14

Targeted testing
Rapid trio-whole exome or whole genome sequencing
Time intensive but cost effective