We describe the clinical case of two childbearing age women with thyroid dysfunction, hypocalcemia, hyperphosphatemia, and high levels of PTH.
Case 1: A 34-year-old woman with infertility for 3 years, microprolactinoma treated with low-dose dopamine agonists, autoimmune primary hypothyroidism and obesity. She had irregular menstrual cycles and fatigue. Weight 130 kg, height 155 cm, cervical acanthosis nigricans and round face. Calcium 6.6 mg/dl, phosphorous 4.9 mg/dl, PTH 244 pg/ml and vitamin D 15 ng/ml.
Case 2: A 40-year-old woman from Nepal with mild osteopenia, subclinical hypothyroidism and hospitalization for severe hypocalcemia and tetany in 2003. She was asymptomatic under treatment with calcium and vitamin D. Weight 63 kg, height 154 cm and brachydactyly of the 5th finger of hand. Calcium 6.3 mg/dl, PTH 546 pg/ml and vitamin D 37 ng/ml at the diagnosis. In both cases, genetic study showed no mutations in the GNAS gene. However, two polymorphisms in heterozygosis, with no clinical relevance to date, was found: case 1 c.393C >T(p.Ile131Ile) and c.1038+55T>C(IVS12+155), and case 2 c.393C >T(p.Ile131Ile) and c.586-42G>A (IVS7-42).
Conclusion: We describe two suspected cases of pseudohypoparathyroidism (PHP) type 1a or 1c with negative genetic test for mutations in the GNAS gene but with a common polymorphism in heterozygosis. No GNAS gene mutations are detected in 3040% of PHP so many of their molecular mechanisms are not known. We think that polymorphism c.393C>T(p.Ile131Ile) could be a new mutation related to PHP.
03 - 07 May 2014
European Society of Endocrinology