Genetics in Cardiology

Question 1

What are the common heart defects in Down Syndrome

Answer 1

Atrial ventricular septal defect
Ventricular septal defect
Atrial septal defect
Patent ductus arteriosus

Question 2

What are the effects of the genes active in Down syndrome?

Answer 2

Cell migration and cell adhesion - roles in heart development

Question 3

What is the characteristic genetic problem associated with Down syndrome?

Answer 3

Over expression of a gene (DSCAM and COL6A2) can result in some sort of heart defect

Question 4

CATCH22 - DiGeorge Syndrome

Answer 4

Cardiac abnormalities
Abnormal facies
thyme aplasia
cleft platate
hypothyroidism
Deletion syndrome on 22q11.2

Question 5

Major cardiac abnormalities associated with DiGeorge syndrome

Answer 5

Interruption of aortic arch
Tetralogy of fallout
ventricular septal defect

Question 6

Why do deletions arise?

Answer 6

LCR-low copy repeats
Non allelic homologous recombination
de novo rearrangement but can be inherited
diversity of phenotype

Question 7

What are the type of mutations in TBX1

Answer 7

new mutations
frameshift nonsense
base pair substitution missense
Can’t attract RNA polymerase

Question 8

pleiotrophic

Answer 8

multiple effects

Question 9

What is hypertrophic cardiomyopathy?

Answer 9

both septum and wall are thickened compared to physiological hypertrophy

Question 10

Phenotype of hypertrophic cardiomyopathy

Answer 10

Increased muscle thickness
Disorganised myocytes
fibrosis

Question 11

locus heterogeneity

Answer 11

Defects in more than one gene can cause a phenotype

Question 12

allelic heterogeneity

Answer 12

different mutations in the same genes can cause the same disease

Question 13

What is the most common cardiac abnormality in DiGEorge syndrome?

Answer 13

Tetralogy of Fallot