Detection of Homozygous Deletions and Mutations in the CDKN2A Gene in Hydatidiform Moles

OBJECTIVE To investigate homozygous deletions and mutations in the CDKN2A gene(p16 INK4a and p14 ARF gene)in hydatidiform moles. METHODS A total of 38 hydatidiform mole samples and 30 villi samples were examined for homozygous deletions in the CDKN2A gene by PCR and for mutations by DHPLC. RESULTS i)Among 38 hydatidiform mole samples, homozygous deletions in the p16 INK4a exon 1 were identified in 5 cases(13.2%),while no homozygous deletions were found in the p16I NK4aexon 1 of 30 early-pregnancy samples.The rates of those deletions in hydatidiform compared to early-pregnancy villi samples was statistically significant(P=0.036).ii)No homozygous deletions in the p14 ARF exon 1 or p16 INK4a exon 2 were found in any of the hydatidiform moles or early-preganancy samples.iii) In all hydatidiform moles and early-pregnancy villi samples,no mutations were detected by DHPLC. CONCLUSION We suggest there may be a close correlation between homozygous deletions in the CDKN2A gene and occurrence of hydatidiform moles variation in the CDKN2A gene is mainly caused by homozygous deletions,while mutations may be not a major cause.