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.