title: Complete deletion of the aprataxin gene: ataxia with oculomotor apraxia type 1 with severe phenotype and cognitive deficit.
abstract: 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.
authors.affiliation: University of Toronto, 555 University Avenue, Ontario, M5G 1X8, Canada.
authors.forename: Grace
authors.initials: G
authors.lastname: Yoon
authors.forename: Robyn
authors.initials: R
authors.lastname: Westmacott
authors.forename: Lynn
authors.initials: L
authors.lastname: Macmillan
authors.forename: Nada
authors.initials: N
authors.lastname: Quercia
authors.forename: Pantelitsa
authors.initials: P
authors.lastname: Koutsou
authors.forename: Anthi
authors.initials: A
authors.lastname: Georghiou
authors.forename: Kyproula
authors.initials: K
authors.lastname: Christodoulou
authors.forename: Brenda
authors.initials: B
authors.lastname: Banwell