Microsatellite genome-wide association study for mandibular prognathism

INTRODUCTION

Attempts have been made to identify susceptibility genes of mandibular prognathism by genome-wide linkage studies, but the results of susceptibility loci are inconsistent. There has been no genome-wide association study of mandibular prognathism. Our objective was to perform a genome-wide association study using 23,465 microsatellite markers to detect mandibular prognathism susceptibility regions.

METHODS

The study was based on the pooled DNA method, including 2 steps of screening on the whole genome and subsequent individual genotyping, with 240 experimental subjects and 360 control subjects from the Japanese population.

RESULTS

Two suggestive associations on chromosomes 1q32.2 (D1S1358i: P = 4.22 × 10(-4)) and 1p22.3 (D1S0411i: P = 6.66 × 10(-4)) were shown, and PLXNA2 and SSX2IP were suggested to be candidate genes; 1p22.3 flanked the region indicated by previous linkage analysis.

CONCLUSIONS

The results of the genome-wide association study showed that 2 loci (1q32.2 and 1p22.3) are likely to be susceptibility regions of mandibular prognathism: 1p32.2 is a novel locus, and identification of 1p22.3 supports the results of previous linkage analysis.

Genome-wide association study for mandibular prognathism using microsatellite and pooled DNA method

INTRODUCTION

The purpose of this study was to extend an association study from chromosome 1 to the whole genome (genome-wide association study) to find susceptibility loci of mandibular prognathism.

METHODS

Two hundred forty patients diagnosed with mandibular prognathism and 360 healthy controls of Japanese descent were recruited. The typing of microsatellites covering the whole genome was conducted using a pooled DNA method. Upon completion of the first and second screenings with pooled DNA, the positive microsatellite markers from both the first and second typings were retyped using individual-subject DNA samples to confirm the significance of allele frequency.

RESULTS

Six microsatellites (D1S0411i, D1S1358i, D3S0810i, D6S0827i, D7S0133i, and D15S0154i) showed differences between allele frequencies of the subjects and controls at P <0.001. D1S0411i, D1S1358i, D3S0810i, D6S0827i, D7S0133i, and D15S0154i were located on chromosomes 1p22.3, 1q32.2, 3q23, 6q23.2, 7q11.22, and 15q22.22, respectively. SSX2IP, PLXNA2, RASA2, TCF21, CALN1, and RORA were suggested as candidate genes.

CONCLUSIONS

The genome-wide association study using microsatellites suggested that 6 loci (1p22.3, 1q32.2, 3q23, 6q23.2, 7q11.22, and 15q22.22) were susceptibility regions of mandibular prognathism. The locus 1p22.3 was supported by a previous linkage analysis, and the other 5 were novel loci.