Friedreich's ataxia/Ataxia telangiectasia

Question 1

inheritance of Friedreich’s ataxia?

Answer 1

autosomal recessive, trinucleotide repeat disorder characterised by a GAA

Question 2

chromosome affected by Friedreich’s ataxia?

Answer 2

chromosome 9

Question 3

typical age of onset Friedreich’s ataxia?

Answer 3

10-15 years old

Question 4

Neurological features of Friedreich’s ataxia?

Answer 4

absent ankle jerks/extensor plantars

cerebellar ataxia

spinocerebellar tract degeneration

Question 5

ophthalmological features of Friedreich’s ataxia

Answer 5

optic atrophy -pale optic disc

Question 6

Other features of Friedreich’s ataxia

Answer 6

hypertrophic obstructive cardiomyopathy (90%, most common cause of death)

diabetes mellitus (10-20%)

high-arched palate

Question 7

how is Friedreich’s ataxia similar to ataxia telangiectasia ?

Answer 7

both have autosomal recessive

cerebellar ataxia

onset in childhood

Question 8

what is ataxia telangiectasia ?

Answer 8

inherited combined immunodeficiency disorders.

Question 9

features of ataxia telangiectasia ?

Answer 9

cerebellar ataxia

telangiectasia (spider angiomas)

IgA deficiency resulting in recurrent chest infections

10% risk of developing malignancy, lymphoma or leukaemia, but also non-lymphoid tumours