Laboratory Medicine Online

Korean Society for Laboratory Medicine (대한진단검사의학회)
권호 표지
DOI QR코드

DOI QR Code

A Case of Pseudohypoparathyroidism Type Ib Caused by Aberrant Methylation in the GNAS Complex Locus

GNAS 메틸화 이상으로 인한 거짓부갑상선기능저하증 Ib 1예

  • Jo, Sung Jin (Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea) ;
  • Han, Eunhee (Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea) ;
  • Jang, Woori (Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea) ;
  • Chae, Hyojin (Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea) ;
  • Kim, Yonggoo (Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea) ;
  • Lee, Gun Dong (Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea) ;
  • Cho, Won Kyoung (Department of Pediatrics, College of Medicine, The Catholic University of Korea) ;
  • Suh, Byung-Kyu (Department of Pediatrics, College of Medicine, The Catholic University of Korea) ;
  • Kim, Myungshin (Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea)
  • 조성진 (가톨릭대학교 의과대학 진단검사의학과) ;
  • 한은희 (가톨릭대학교 의과대학 진단검사의학과) ;
  • 장우리 (가톨릭대학교 의과대학 진단검사의학과) ;
  • 채효진 (가톨릭대학교 의과대학 진단검사의학과) ;
  • 김용구 (가톨릭대학교 의과대학 진단검사의학과) ;
  • 이건동 (가톨릭대학교 의과대학 진단검사의학과) ;
  • 조원경 (가톨릭대학교 의과대학 소아청소년과) ;
  • 서병규 (가톨릭대학교 의과대학 소아청소년과) ;
  • 김명신 (가톨릭대학교 의과대학 진단검사의학과)
  • Received : 2016.06.13
  • Accepted : 2016.08.18
  • Published : 2017.04.30
⟨ Previous Next ⟩

Abstract

Pseudohypoparathyroidism (PHP) is a rare disorder caused by genetic and epigenetic aberrations in the GNAS complex locus resulting in impaired expression of stimulatory G protein ($Gs{\alpha}$). PHP type Ib (PHP-Ib) is characterized by hypocalcemia and hyperphosphatemia due to renal resistance to the parathyroid hormone, and is distinguished from PHP-Ia by the absence of osteodystrophic features. An 11-yr-old boy presented with poor oral intake and cramping lower limb pain after physical activity. Laboratory studies revealed hypocalcemia, hyperphosphatemia, and increased parathyroid hormone levels. The GNAS complex locus was evaluated using the methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) assay. Gain of methylation in the NESP55 domain and loss of methylation in the antisense (AS) transcript, XL, and A/B domains in the maternal allele were observed. Consequently, we present a case of PHP-Ib diagnosed using MS-MLPA.

Keywords

Acknowledgement

Supported by : The Catholic University of Korea