Endocrine Abstracts

Background: Hypoparathyroidism is a rare endocrine disorder that is rarely seen in clinical practice. Resistance to parathyroid hormone (PTH) gives rise to specific developmental and biochemical abnormalities allowing for a diagnosis of pseudohypoparathyroidism (PHP) [1]. Uniquely the skeletal defects seen in pseudohypoparathyroidism can occur in the absence of its associated biochemical sequelae, a condition referred to as pseudopseudohypoparathyroism (PPHP). The following case highlights this disorder.

Case: A 60-year-old female presented with generalized seizures. Past history noted diabetes and a cerebrovascular accident. Medications included metformin and once daily insulin. Examination revealed a short stature with height of 153 cm and an increased body mass index of 28.6 kg/m² There was brachydactyly of the 4th and 5th metacarpals bilaterally without involvement of the metatarsals. Neurological exam was negative for cognitive impairment. Routine blood investigations yielded normal complete blood count, renal and thyroid function with a markedly elevated low-density lipoprotein cholesterol of 219 mg/dl (reference range < 100). Her calcium, phosphorus and PTH were within range. Radiographs were negative for arthropathy. Antiepileptic therapy, a statin and antiplatelet agents were initiated. Discharge plan included lifestyle modifications and outpatient clinic follow up.

Conclusion: Patients with PPHP have mutations on the paternally inherited allele and have the PHP phenotype alone without hormonal resistance or the severe obesity.[2] Adult short stature is common to both PPH and PPHP due to early closure of the epiphyses of the long bones.[2] Increasing the likelihood of metabolic syndrome and diabetes mellitus. Clinical acumen is required to ascertain the physical findings of PPHP as patients often present with unrelated symptoms or diseases. Upon detection of these signs PTH and calcium measurements must be done so as to not miss the sinister differential of PHP.

References: 1. Bilezikian JP. Hypoparathyroidism. J Clin Endocrinol Metab. 2020;105(6):1722-1736. doi:10.1210/clinem/dgaa1132. Germain-Lee EL. Management of pseudohypoparathyroidism. Curr Opin Pediatr. 2019;31(4):537-549. doi:10.1097/MOP.0000000000000783