Endocrine Abstracts

Introduction: Primary hypoparathyroidism (PH) is a rare condition. After surgery and chronic alcoholism, an autoimmune disease is the most common etiology and must specifically be considered in the context of a patient with other autoimmune endocrine diseases.

Case report: MASD a male caucasian patient aged 31, was admitted to the emergency department because of perioral and hand paresthesias, and carpal spasm, in the context of a generalized anxiety reaction. A previous diagnosis of Hashimoto’s thyroiditis treated with levothyroxine was reported. There were no other known diseases nor previous surgeries, alcohol consumption or drug use. Family history was unremarkable as it was physical examination, except for positive Chvostek and Trousseau signs. Analytical evaluation revealed hypocalcaemia with increased serum phosphate and normal albumin and arterial pH; hypercalciuria was found. Serum PTH was low with normal 25-hydroxyvitaminD levels and normal parameters of bone formation and reabsorption as well as normal bone densitometry. Thyroid function was normal under therapy. Normal adrenal and pituitary function were found. Antibodies against parathyroid cells were negative. Genetic testing revealed the c.2968A>G(p.Arg990Gy) polymorphism at exon 6 of the calcium sensing receptor (CASR) gene.

Discussion: PH is a very rare condition. In this patient, the presence of known Hashimoto’s thyroiditis made autoimmune PH the most likely diagnosis, suggesting a polyglandular autoimmune disease. However parathyroid auto-antibodies were negative and a specific polymorphism of the CASR gene was found that according to published data may be associated with gain of function of calcium sensor. Reported prevalence of this polymorphism is so low, that it must be considered causative in this patient. In conclusion in this young patient with autoimmune thyroid disease, PH was found in relation to a specific polymorphism of the CASR gene. A rose is not always a rose.