DR Medhat MRCP

Herido-familaial ataxia :
A. Friedrich`s ataxia :
- Friedreich's ataxia is the most common of the early-onset hereditary
ataxias.
- It is an autosomal recessive, trinucleotide repeat disorder characterised by
a GAA repeat in the X25 gene on chromosome 9 (frataxin).
- Friedreich's ataxia is unusual amongst trinucleotide repeat disorders in not
demonstrating the phenomenon of anticipation.
- The typical age of onset is 10-15 years old
- Neurological features
o Absent ankle jerks/extensor plantars.
o Cerebellar ataxia.
o Optic atrophy.
o Spinocerebellar tract degeneration
- Other features:
o HOCM (90%, most common cause of death).
o Diabetes mellitus (10-20%).
o High-arched palate
هام جدا
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