Complete deletion of the aprataxin gene: ataxia with oculomotor apraxia type 1 with severe phenotype and cognitive deficit
- Grace Yoon1,
- Robyn Westmacott2,
- Lynn MacMillan2,
- Nada Quercia2,
- Pantelitsa Koutsou3,
- Anthi Georghiou3,
- Kyproula Christodoulou3,
- Brenda Banwell2
- 1University of Toronto, 555 University Avenue, Ontario, M5G 1X8, Canada
- 2The Hospital for Sick Children, 555 University Ave, Toronto, Ontario, M5G 1X8, Canada
- 3The Cyprus Institute of Neurology and Genetics, Nicosia, Nicosia, 1424, Cyprus
- Published 2 February 2009
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.
Competing interests: None.