Adult-onset pseudohypoparathyroidism type 1B diagnosed by methylation analysis: A case report and diagnostic considerations

Adult-onset PHP1B should be considered in the differential diagnosis of unexplained hypocalcemia with elevated PTH, even in the absence of Albright hereditary osteodystrophy. Because conventional sequencing cannot detect imprinting defects, epigenetic testing such as MS-MLPA is essential for definitive diagnosis. Increased awareness of atypical, late-onset presentations can aid in timely diagnosis and appropriate management.