Ataxia with oculomotor apraxia type 1 (AOA1) is a recently described autosomal-recessive neurodegenerative condition of childhood onset. It is caused by mutations in the APTX gene, which encodes the protein aprataxin. Clinical features include gait and limb ataxia, dysarthria, oculomotor apraxia, mild peripheral neuropathy and progression of neurological deficits.1 Some patients manifest parkinsonian symptoms or mental retardation, although the latter has been reported predominantly in Japanese patients.2 We report a patient with homozygous deletion of APTX, who presented with behavioural changes (social withdrawal), and subsequent rapid progression of neurological symptoms associated with severe cognitive decline. We suggest that complete deletion of APTX is associated with a more severe phenotype than that associated with point mutations.

CASE REPORT

The patient is the second child of first-cousin Pakistani parents, and has two healthy brothers who are neurologically and cognitively normal. Prenatal, delivery and early neonatal history were unremarkable. Early developmental milestones were met at the appropriate times and social development was normal. At age 5 years, she began to withdraw from social contact in school and became very shy. She also demonstrated difficulties in acquiring new language. She was then noticed to become more unsteady while walking and, by 5.5 years, she began to fall. At age 6.5 years, …