Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

A GAA-repeat in the X25 gene is causing Friedreich's ataxia (FRDA), a common neurodegenerative disease and >20% of FRDA patients develop type II diabetes (T2D). Linkage has previously been detected between T2D and chromosome 9p13-q21, the region that harbours the X25 gene, but association studies of this gene in T2D have been contradicting. Here, we examined whether genetic variation in the X25 gene is associated with risk for T2D. The GAA-repeat and 18 single nucleotide polymorphisms (SNPs) covering the X25 gene were genotyped in 220 trios in which the affected offspring had abnormal glucose tolerance. Any nominally significant findings were examined in an independent sample consisting of 523 individuals with T2D and 326 healthy controls. Previously reported results were analysed together with our data using a meta-analysis approach. There was no association between the GAA-repeat and T2D susceptibility in our study, which was supported by the meta-analysis including all previous publications. One SNP (rs2498429), 8.2 kb downstream of X25, was nominally associated with T2D in the trios (P=0.02) and showed a trend of association in the same direction in the case-controls (P=0.08; combined permuted P=0.01). Further analysis showed that the nine-marker haplotype containing the rare allele of rs2498429 was nominally associated with T2D in the trios (P<0.01) as well as in the case-controls (P=0.03). In conclusions, this study excludes a role of genetic variation within the X25 gene, but instead suggests that genetic variation downstream the X25 gene, may increase risk for T2D.

Original publication

DOI

10.1038/sj.ejhg.5201413

Type

Journal article

Journal

Eur J Hum Genet

Publication Date

07/2005

Volume

13

Pages

849 - 855

Keywords

Adult, Aged, Case-Control Studies, Diabetes Mellitus, Type 2, Female, Finland, Friedreich Ataxia, Gene Frequency, Genetic Predisposition to Disease, Genetic Variation, Glucose Intolerance, Haplotypes, Humans, Iron-Binding Proteins, Linkage Disequilibrium, Male, Middle Aged, Trinucleotide Repeats