Clinical and genetic analysis of a case of type Ib pseudohypoparathyroidism complicated with hypokalemia

VernacularTitle:1例Ⅰb型假性甲状旁腺功能减退症合并低钾血症的临床和遗传特征分析
Author: Jingzun XU ¹ ; Xueyao YIN
Author Information

1. 浙江大学医学院附属邵逸夫医院内分泌科，杭州　310000
Keywords: Type Ib pseudohypoparathyroidism; Methylation defect; Hypokalemia
From: Chinese Journal of Endocrinology and Metabolism 2024;40(6):525-528
CountryChina
Language:Chinese
Abstract: A young female patient with type Ⅰb pseudohypoparathyroidism(PHP) complicated with hypokalemia was retrospectively analyzed. She experienced recurrent episodes of limb weakness with bilateral upper limb spasms. Laboratory tests revealed low blood calcium, high blood phosphate, elevated parathyroid hormone, low urine calcium, and hypokalemia. Genetic testing did not detect mutations in guanine nucleotide-binding protein α-stimulating activity polypeptide(GNAS) or syntaxin 16(STX16) genes, but identified a maternal heterozygous mutation in solute carrier family 4 member A1(SLC4A1) gene. Multiple ligation-dependent probe amplification(MLPA) indicated GNAS antisense transcript(GNAS-AS), non-coding exons(GNAS-A/B), extra-large Gsα variant(GNAS-XLα) methylation loss, and neuroendocrine secretory protein 55(NESP55) hypermethylation. Through analysis of her diagnosis and treatment process and review of relevant literature, we aim to enhance understanding and management of type Ib PHP.