SCA2 is not a major locus for ADCA type I in French families

✍ Scribed by Cancel, Géraldine ;Stevanin, Giovanni ;Dürr, Alexandra ;Chneiweiss, Hervé ;Penet, Christiane ;Pothin, Yolaine ;Agid, Yves ;Brice, Alexis

• Book ID: 101446632
• Publisher: John Wiley and Sons
• Year: 1995
• Tongue: English
• Weight: 357 KB
• Volume: 60
• Category: Article
• ISSN: 0148-7299
• DOI: 10.1002/ajmg.1320600507

✦ Synopsis

Autosomal dominant cerebellar ataxias (ADCA) of type I, a group of clinically heterogeneous neurodegenerative disorders, are known to be genetically heterogeneous since a second locus for ADCA type I (SCA2) has been identified on the long arm of chromosome 12. Linkage analysis was performed in 7 French ADCA type I families in order to estimate its frequency. We analysed 121 individuals, 39 of whom were affected. In 6 families, the SCA2 candidate interval, spanning 12.8 cM, was excluded by bi-and multipoint analysis. In one family (SAL-315), however, the maximal positive lod score reached 2.03 at the D12S79 locus. A posterior probability of 94% in favor of linkage to SCA2 was calculated by homogeneity analysis. The clinical profile of this family was similar to that of previously described SCAl and non-SCAl families, except that dementia was observed in 2 out of 6 patients. This may be a clinical idiosyncrasy in this family and was insufficient for a genotype-phenotype correlation.