Mutations in genes encoding hepatocyte nuclear factor (HNF) are responsible for three of the five subtypes of maturity-onset diabetes of the young (MODY). This observation and molecular studies indicate that the HNF network is required for normal function of pancreatic β-cells. This suggests that transcription factors involved in this complex network are candidates for genetic defects in MODY. Because the HNF-3β gene is implicated in this network, we screened it for mutations in 21 probands of French ancestry with clinical diagnosis of MODY and early-onset type 2 diabetes. All of the five known MODY genes, HNF-4α, glucokinase, HNF-1α, HNF-1β, and IPF1, were previously excluded as being the cause of diabetes in these families. By direct sequencing, we identified two transitions, an A-to-G at position -213 and a C-to-T at position -63 in the promoter and exon 1, respectively, of the HNF-3β gene. A G-to-C transversion at position +32 in the intron I and three transitions, C-to-T at position 291, A-to-G at position 837, and G-to-A at position 1188 in the exon 3, resulting in noncoding mutations Ala97Ala, Gly279Gly, and Gln396Gln, respectively, were also identified. The allele frequencies were not significantly different between a control group and MODY probands. Familial segregation studies and linkage analysis showed that genetic variation in the HNF-3β gene is unlikely to be the cause of early- onset type 2 diabetes in these Caucasian families.
|Number of pages||3|
|Publication status||Published - 1 Feb 2000|
ASJC Scopus subject areas
- Internal Medicine
- Endocrinology, Diabetes and Metabolism