Spinocerebellar ataxia type 7: a distinctive form of autosomal dominant cerebellar ataxia with retinopathy and marked genetic anticipation.
When a child presents with progressive ataxia, there is a broad differential diagnosis and a very long list of potential investigations. Spinocerebellar ataxia type 7 presenting in infancy is a rare condition where a presumptive diagnosis can be made based on the clinical features alone. These include rapidly progressive ataxia, retinopathy and autosomal dominant inheritance with marked genetic anticipation of paternal origin. The father of the infant may manifest minimal symptoms at a time when the infant is severely affected. Diagnosis is confirmed by the demonstration of an expansion of a CAG repeat in the coding region of the gene on chromosome 3p. We present a case to illustrate the diagnostic difficulties. Antenatal diagnosis was performed in two subsequent pregnancies.
Grattan-Smith
P J
PJ
Department of Neurology, Royal Alexandra Hospital for Children, Westmead, New South Wales, Australia.
Healey
S
S
Grigg
J R
JR
Christodoulou
J
J
D017809:Fatal Outcome; D005260:Female; D006801:Humans; D007223:Infant; D015418:Optic Atrophies, Hereditary / Q000209:etiology*; D011296:Prenatal Diagnosis; D012174:Retinitis Pigmentosa / Q000209:etiology*; D020754:Spinocerebellar Ataxias / Q000150:complications / Q000175:diagnosis* / Q000235:genetics; D019680:Trinucleotide Repeat Expansion