A Novel IVS2-1G>A Mutation Causes Aberrant Splicing of the HRPT2 Gene in a Family with Hyperparathyroidism-Jaw Tumor Syndrome
Authors
Sung-Dae Moon ; Jae-Hyun Park ; Eun-Min Kim ; Ju-Hee Kim ; Je-Ho Han ; Soon-Jib Yoo ; Kun-Ho Yoon ; Moo-Il Kang ; Kwang-Woo Lee ; Ho-Yong Son ; Sung-Koo Kang ; Se-Jeong Oh ; Kyung-Mi Kim ; Sung-Joo Kim Yoon ; Jae-Gahb Park ; Il-Jin Kim ; Hio Chung Kang ; Soon-Won Hong ; Kyung-Rae Kim ; Bong-Yun Cha
Citation
JOURNAL OF CLINICAL ENDOCRINOLOGY & METABOLISM, Vol.90(2) : 878-883, 2005
HRPT2, the gene associated with hyperparathyroidism-jaw tumor (HPT-JT) syndrome, was previously mapped to 1q24-q32. It was recently cloned, and several germline mutations were found to predispose to HPT-JT syndrome. We sequenced the complete HRPT2 coding sequence and splice-junctional regions in a Korean family with HPT-JT syndrome and identified a novel germline mutation, IVS2-1G>A in intron 2, that caused the autosomal dominant trait of HPT-JT syndrome in this family. RT-PCR and sequencing of the transcripts revealed that this splicing mutation generated alternative splicing errors leading to the formation of two different transcripts, one with exon 3 deleted, the other lacking the first 23 bp of exon 3 due to the use of an internal splice acceptor in exon 3. Translation of both transcripts results in premature termination. In addition, we detected two novel somatic mutations of HRPT2 in malignant parathyroid tumors from the affected individuals. One, 85delG, causes premature termination; the other, an 18 bp in-frame deletion of 13_30delCTTAGCGTCCTGCGACAG, suggests that this region may be important in the development of the parathyroid carcinomas in HPT-JT syndrome. These findings provide further evidence that mutation of HRPT2 is associated with the formation of parathyroid tumors in HPT-JT syndrome.