Genetics

Question 1

what type of inheritance is DMD

Answer 1

x-linked recessive

Question 2

what type of inheritance is Huntington disease

Answer 2

autosomal dominant

Question 3

what is signs/symptoms in DMD

Answer 3

• delay in motor development
• pelvic and shoulder girdle weakness
• calf hypertrophy
• Gower’s sign
• toe walking

Question 4

what causes DMD

Answer 4

dystrophin deficiency

Question 5

what investigations are done for DMD

Answer 5

serum CK (very elevated)
muscle biopsy

Question 6

features of Huntington disease

Answer 6

dementia

involuntary movements

Question 7

what pathological signs are seen in Huntington’s

Answer 7

• caudate atrophy
• putamen atrophy
• loss of GABAergic neurons of the basal ganglia
• enlargement of the frontal horns of the lateral ventricles

Question 8

what does the Huntington gene code for

Answer 8

CAG (which codes for glutamine)

Question 9

what is the pathology of alzheimer disease

Answer 9

Loss of cortical neurones
Neurofibrillary tangles (intracellular)
Senile plaques (extracellular)

Question 10

what are senile plaques composed of

Answer 10

amyloid β protein

also called amyloid plaques

Question 11

what are the mutations linked with Alzheimer disease

Answer 11

APP mutations (chromosome 21)
Presenilin 1 (chromosome 14)
Presenilin 2 (chromosome 1)

Question 12

what ApoE allele predisposes to Alzheimer disease

Answer 12

e4