Endocrine Abstracts

JOINT3659

Introduction: Pseudohypoparathyroidism (PHP) is a rare endocrine disorder of genetic origin, which can be either sporadic or hereditary. It results from target tissue resistance to parathyroid hormone (PTH), leading to clinical and biological abnormalities. Several forms exist, varying according to resistance to other hormones and the presence of dysmorphic syndromes, with heterogeneous clinical expression, even among patients carrying the same mutation. We report the case of a patient in whom pseudohypoparathyroidism was revealed by bone pain.

Case Report: A 15-year-old patient, born to non-consanguineous parents and without notable family history, presented to our department with bone pain. Physical examination was unremarkable. Laboratory tests revealed hypocalcemia (1.5 nmol/l), hyperphosphatemia (2.26 nmol/l), and elevated PTH (455 pg/mL). Further investigations showed no hypomagnesemia, vitamin D deficiency, or renal insufficiency. A follow-up assessment was conducted and revealed no abnormalities. The patient exhibited no cardiovascular, including QT prolongation, and no neuromuscular signs of hypocalcemia, such as cramps, paresthesias, or tetany. Additionally, there were no morphological anomalies like brachydactyly, rounded face, obesity, or growth retardation. The stomatological examination was normal, and no resistance to other hormones, particularly TSH or gonadal hormones, was identified. The diagnosis of PHP was established. Genetic testing was not performed due to its unavailability. The patient was treated with oral calcium carbonate and an alpha-hydroxylated vitamin D derivative, leading to significant improvement in bone pain.

Discussion and conclusion: PHP is characterized by elevated PTH, hypocalcemia, and hyperphosphatemia, in the absence of vitamin D deficiency, hypomagnesemia, or renal insufficiency. Its different subtypes are defined based on clinical criteria (Albright hereditary osteodystrophy, Progressive osseous heteroplasia, Acrodysostosis) and biological features, notably resistance to TSH and other hormones. In our patient, the absence of short stature, Albright’s dysplasia, ectopic ossifications, hypothyroidism, and hypogonadism suggests PHP type 1B. Genetic testing would be necessary to confirm the diagnosis.