Short Communication
Journal of Human Genetics (2005) 50, 155–157; doi:10.1007/s10038-005-0233-0
Post-zygotic de novo trinucleotide repeat expansion at spinocerebellar ataxia type 7 locus: evidence from an Indian family
Uma Mittal1, Sanghamitra Roy1, Satish Jain2,*, Achal K Srivastava2 and Mitali Mukerji1
- 1Functional Genomics Unit, Institute of Genomics and Integrative Biology, CSIR, Mall Road, Delhi, 110007, India
- 2Neuroscience Centre, All India Institute of Medical Sciences, New Delhi, India
Correspondence: Mitali Mukerji, Functional Genomics Unit, Institute of Genomics and Integrative Biology, CSIR, Mall Road, Delhi, 110007, India. Fax: 91-11-27667471. E-mail: mitali@igib.res.in
*Present address: Indian Epilepsy Centre, Defence Colony, New Delhi, India
Received 19 October 2004; Accepted 28 December 2004; Published online 5 March 2005.
Abstract
Spinocerebellar ataxia type 7 (SCA7) is an autosomal dominant cerebellar ataxia caused by CAG repeat expansion. We found expansion at SCA7 locus in only two out of 235 Indian families clinically diagnosed for ataxia. In one of the families, a de novo mutation was observed wherein a paternal allele in intermediate range of 31 CAG repeats expanded to 59 in the offspring leading to the disease. No expanded alleles were observed in the sperm of the transmitting parent by small pool PCR. This suggests that de novo expansion by a pre-zygotic event is unlikely and could be post-zygotic. SCA7 expanded alleles from the two families were present on different genetic backgrounds, indicating multiple origins of the mutation.
Keywords:
Spinocerebellar ataxia 7 (SCA7), Post-zygotic, De novo mutation, CAG repeat, Repeat instability
MORE ARTICLES LIKE THIS
These links to content published by NPG are automatically generated.
RESEARCH
Certain Animal PoisonsNature Letters to Editor (09 Oct 1879)
Rett syndrome is caused by mutations in X-linked MECP2, encoding methyl-CpG-binding protein 2Nature Genetics Letter (01 Oct 1999)
Quasi-stellar Sources, Supernovae and NovaeNature Article (21 Oct 1967)
Some Remarks on the Rev. J. G. Wood's Explanatory Index to ????Waterton's Wanderings???Nature Letters to Editor (31 Jul 1879)
SMARCA2 and THAP11: potential candidates for polyglutamine disorders as evidenced from polymorphism and protein-folding simulation studiesJournal of Human Genetics Original Article
