No diabetes-associated mutations in the coding region of the hepatocyte nuclear factor-4gamma gene (HNF4G) in Japanese patients with MODY.
OBJECTIVE
Mutations in the transcription factor hepatocyte nuclear factor (HNF)-4alpha are the cause of one form of maturity-onset diabetes of the young, MODY1. The HNF-4gamma is structurally related to HNF-4alpha and is expressed together with HNF-4alpha in pancreatic islets. We therefore tested the hypothesis that genetic variation in the HNF-4gamma gene (HNF4G) is associated with MODY in Japanese subjects.


METHODS
We screened the protein coding region of HNF4G (exons 3-11) for mutations in 57 unrelated Japanese subjects with MODY by amplifying each exon and adjacent intron region using the polymerase chain reaction (PCR) and specific primers and then directly sequencing the PCR products. The frequency of each variant was compared between patients with MODY and a group of non-diabetic subjects.


RESULTS
We found ten sequence variants, two of these were located in exons: exon 6, a silent substitution in codon 144, c.432A/G and exon 7, a G-to-A substitution in codon 190 (c.570G/A) resulting in a conservative Met-to-Ile substitution (M/I190) in the putative ligand-binding region of HNF-4gamma protein. The remaining eight variants were located in introns. There was no significant difference in the frequency of these polymorphisms between subjects with MODY and non-diabetic control subjects.


CONCLUSIONS
Genetic variation in the coding region of HNF4G is unlikely to be a major cause of MODY in Japanese people.
Hara
M
M
Howard Hughes Medical Institute, The University of Chicago, Illinois 60637, USA.
Wang
X
X
Paz
V P
VP
Cox
N J
NJ
Iwasaki
N
N
Ogata
M
M
Iwamoto
Y
Y
Bell
G I
GI
D000595:Amino Acid Sequence; D044466:Asian People / Q000235:genetics*; D001483:Base Sequence; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D015331:Cohort Studies; D004268:DNA-Binding Proteins; D003924:Diabetes Mellitus, Type 2 / Q000235:genetics*; D005091:Exons; D005787:Gene Frequency; D014644:Genetic Variation; D051557:Hepatocyte Nuclear Factor 4; D006801:Humans; D007438:Introns; D007564:Japan; D008969:Molecular Sequence Data; D010750:Phosphoproteins / Q000235:genetics*; D016133:Polymerase Chain Reaction; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics; D012016:Reference Values; D014157:Transcription Factors / Q000235:genetics*
D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D004268:DNA-Binding Proteins; C496592:HNF4A protein, human; C496597:HNF4G protein, human; D051557:Hepatocyte Nuclear Factor 4; C403128:MLX protein, human; D010750:Phosphoproteins; D018160:Receptors, Cytoplasmic and Nuclear; D014157:Transcription Factors