Mutation analysis of spinocerebellar ataxia type 1 (SCA1) in a large Iakut kinship of Eastern Siberia
- and others
We have studied 131 patients with autosomal dominant cerebellar ataxia clinically and pathologically expressed as olivopontocerebellar atrophy. The disease in this Siberian kinship has been genetically linked to the SCA1 gene on chromosome 6p, and the pedigree was screened for the recently described CAG repeat expansion in this gene using the GeneScan program (ABI). The normal allele in the affected individuals had 26 to 32 repeats, and among 424 analyzed normal alleles of the unaffected members of the kinship, unrelated controls and patients with other neurological disorders, the range of repeat numbers was 26 to 37, with 92% within 28 to 30 repeats. All 65 normal alleles in which the repeat area has been sequenced show a CAT or CATCAGCAT interruption between the first and the second stretches of 10 to 17 CAG repeats. The SCA1 allele was extended to 39 to 60 uninterrupted repeats in all fifty-nine analyzed ataxia patients. Repeat numbers of 40 to 55 were also found in thirty-nine of 105 tested unaffected first and second degree relatives. Two patients and an unaffected child were homozygous for the elongated allele. In seven of 10 paternal transmissions an increase of 2 to 11 repeats have occurred; in nine maternal transmissions the repeat numbers remained the same or grew for just one repeat. Mutation analysis provides new opportunities in diagnosis and risk assessment of spinocerebellar ataxia type 1.
- OSTI ID:
- 134213
- Report Number(s):
- CONF-941009-; ISSN 0002-9297; TRN: 95:005313-0949
- Journal Information:
- American Journal of Human Genetics, Vol. 55, Issue Suppl.3; Conference: 44. annual meeting of the American Society of Human Genetics, Montreal (Canada), 18-22 Oct 1994; Other Information: PBD: Sep 1994
- Country of Publication:
- United States
- Language:
- English
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