A case of pseudohypoparathyroidism type-1a

Written by Szántó Zsuzsanna, Kun Imre Zoltán

Pseudohypopara¬thyroidism (PHP) is a rare genetic disease (3.4 cases/million), caused by a reduced sensitivity of parathyroid hormone receptors (PTH). The 38-years-old male presented a grand mal seizure in December 2007, CT-scan showing multiple brain calcifications. The suspicion of PHP arose due to characteristic phenotype of Albright’s hereditary osteodystrophy (AHO): short stature (height 164cm), obesity (BMI 35kg/m²), round face, short neck, brachydactyly, subcutaneous firm nodules in soft tissues, genu valgum, mild/moderate mental retardation. The laboratory showed a high intact PTH level (iPTH: 175.5 pg/ml, normal: 15-65) associated with hypocalcemia (Ca2+: 1.46 mmol/l, n: 2.1-2.55), low urinary calcium (0.02 mmol/24h, n: 2.5-8), a tendency to hyperphos¬phatemia (1.51mmol/l, n: 0.74-1.52), as well as primary hypo¬thyroidism (TSH: 5.75 mUI/L, n: 0.27-4.2 and FT4: 0.87 ng/dL, n: 0.93-1.71). Hand and foot X-rays identified soft tissue calcifications. The presence of clinical picture of AHO, the high iPTH level beside hypocalcemia and low urinary calcium excretion, multiple soft tissue calcifications, associated with mental retardation and other endocrinopathy (primary hypothyroidism) sustain the diagnosis of PHP type-1a. Treatment targets the normalisation of serum calcium and iPTH levels, but supplementation with calcium and vitamin D3 could not control successfully iPTH, so we tried “off-label” use of calcimimetic cinacalcet for a short period of time. We also applied levothyroxine substitution.


Keywords: pseudohypoparathyroidism, Albright’s hereditary osteodystrophy, ectopic calcifications, cinacalcet.

Print   Email