Genetics CNS conditions

Question 1

Inheritance pattern of Duchenne muscular dystrophy

Answer 1

X-linked recessive

Question 2

Cause of DMD (2)

Answer 2

70%- large deletions in dystrophin gene

30%- point mutations, indels

Question 3

Signs of DMD (3)

Answer 3

Gower’s sign
Toe walking
calf hypertrophy

Question 4

Tests in DMD (4)

Answer 4

Raised CK
EMG
Muscle biopsy
Genetic testing

Question 5

Site of atrophy in Huntington’s disease

Answer 5

Caudate nucleus

Question 6

Cause of HD

Answer 6

Autosomal dominant triplet repeat (CAG) disorder

Question 7

Autosomal dominant Alzheimers genes (3)

Answer 7

APP
presenilin 1
presenilin 2

Question 8

ApoE genotype predisposing to AD

Answer 8

e4 allele

Question 9

Inheritance of neurofibromatosis (3)

Answer 9

Autosomal dominant; variable expressivity; NF2 is 50% de novo

Question 10

Signs of NF (4)

Answer 10

Cafe au lait patches
Neurofibromas
Lisch nodules (harmless hamartomas on the iris)
NF2- bilateral acoustic neuromas

Question 11

Signs of tuberous sclerosis (4)

Answer 11

Shagreen patches
Cafe au lait patches
Subungual fibromas
Epilepsy