Autosomal dominant cerebellar ataxia type I in Martinique (French West Indies): Genetic analysis of three unrelated SCA2 families

Agnès Lezin, Jenny Martial, Géraldine Cancel, Giovanni Stevanin, Alexander Dürr, Yves Agid, Alexis Brice, Didier Smadja, Jean-Claude Vernant, Georges-Gabriel Buisson, Rémy Bellance, Hervé Chneiweiss
Hum Genet. 1996-05-01; 97(5): 671-676
DOI: 10.1007/BF02281881

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1. Hum Genet. 1996 May;97(5):671-6.

Autosomal dominant cerebellar ataxia type I in Martinique (French West Indies):
genetic analysis of three unrelated SCA2 families.

Lezin A(1), Cancel G, Stevanin G, Smadja D, Vernant JC, Dürr A, Martial J,
Buisson GG, Bellance R, Chneiweiss H, Agid Y, Brice A.

Author information:
(1)Laboratoire de Biologie Moléculaire, CTS-Höpital Perre
Zobda-Quitman,Fort-de-France, Martinique.

Autosomal dominant cerebellar ataxias (ADCAs) are a group of neurodegenerative
disorders that are clinically and genetically heterogeneous. We report here a
genetic linkage study, with five chromosome 12q markers, of three Martinican
families with ADCA type 1, for which the spinocerebellar ataxia 1 (SCA1) locus
was excluded. Linkage to the SCA2 locus was demonstrated with a maximal lead
score of 6.64 at theta = 0.00 with marker D12S354. Recombinational events
observed by haplotype reconstruction demonstrated that the SCA2 locus is located
in an approximately 7-cM interval flanked by D12S105 and D12S79. Using the
z(max)-1 method, multipoint analysis further reduced the candidate interval for
SCA2 to a region of 5 cM. Two families shared a common haplotype at loci spanning
7 cM, which suggests a founder effect, whereas a different haplotype segregated
with the disease in the third family. Finally, a mean anticipation of 12+/-14
years was found in parent-child couples, with no parental sex effect, suggesting
that the disease might be caused by an expanded and unstable triplet repeat.

DOI: 10.1007/BF02281881
PMID: 8655151 [Indexed for MEDLINE]

Auteurs Bordeaux Neurocampus