Genetics

Question 1

X linked conditions

Answer 1

Haemophilia

Duchenne’s + Becker muscular dystrophy

Question 2

Autosomal dominant conditions

Answer 2

Huntingtons
Myotonic dystrophy
Familial cancer syndromes
Neurofibromatosis

Question 3

What conditions are caused by deletions?

Answer 3

Duchenne’s + Becker muscular dystrophy
A-thalassaemia
Congenital adrenal hyperplasia

Question 4

What conditions are caused by mutations?

Answer 4

Sickle cell

CF

Question 5

What is mendelian inheritance?

Answer 5

Transmission of inherited traits caused by variation in a single gene

Question 6

What disorders can be screened for in consanguinous couples?

Answer 6

Sickle cell
Thalassaemias
Tay-Sachs disease

Question 7

Causes of DS

Answer 7

Meiotic non-dysjunction
Translocation
Mosaicism

Question 8

S+S of DS

Answer 8

Dysmorphic features: oblique palpable fissures, epicanthic folds, Brushfield spots on iris, brachycephalic skull, low set ears, large protruding tongue
Single palmar crease, wide sandal gap 
Short stature 
Hypotonia 
Delayed development

Question 9

Complications of DS

Answer 9

Congenital heart disease - usually AVSD 
Duodenal atresia 
Leukaemia 
Thyroid problems 
Diabetes 
Presenile dementia 
Low fertility in males

Question 10

What are the genetics of Fragile X?

Answer 10

CCG repeats >200 (mutation in FMR1 gene)

Question 11

What are the genetics in Prader Willi?

Answer 11

Deletion of paternally inherited ch15

Question 12

What genetic change causes CML?

Answer 12

Philadelphia chromosome