Pseudohypoparathyroidism-A Rare Cause of Seizures in a Young Male

Abstract

Introduction: Symptomatic hypocalcemia has a variety of underlying etiologies,with hypoparathyroidism and vitamin D deficiency being the most common. However,rarer etiologies such as pseudohypoparathyroidism, as is present in the current case, should not be overlooked. Pseudohypoparathyroidism (PHP) is a heterogeneous group of disorders characterized by parathyroid hormone (PTH) resistance. The diagnosis of this rare genetic condition is often delayed,due to its myriad presentations,leading to an initially inappropriate approach and therapy.

Materials: A 19-year-old male,K/C/O seizure disorder since 18 years,presented to ER in generalized convulsive status epilepticus since 2 hours.Developmentally he had poor growth spurt. No h/o trauma, fever, vomiting, headache. Patient continued to have seizures occasionally despite being compliant to Tab Sodium Valproate 250mg BD.O/E: Patient was drowsy but arousable. He had short stature.Height-35 kg, Weight-136 cm and BMI 18.92 kg/m2.Bilateral cataractous lens+. Examination of limbs revealed brachydactyly of the fingers and fourth toes. Chvostek and Trousseau signs were positive. Knuckle knuckle Dimple Dimple Sign+ Result: ECG showed showed prolonged QT interval. Blood investigations showed Serum calcium-5.8, Serum phosphorus-8.7, iPTH-193, TSH-15.4. MRI brain revealed diffuse bilateral calcifications of basal ganglia. Given the clinical,radiographic and laboratory findings, diagnoses of PHP type Ia with primary hypothyroidism was made.Patient was admitted to wards,hypocalcemia corrected with intravenous and oral calcium and vitamin D.Discharged on 50 ug levothyroxine, oral calcium, vitamin D3 oral solution weekly. The patient is being followed up at half monthly intervals and has remained seizure free since discharge.

Conclusion: PHP type Ia (GNAS gene mutation) is the most common form of PHP and associated with Albright's hereditary osteodystrophy (AHO), resistance to multiple hormones. This case stresses the pivotal role of a complete biochemical investigation of the calcium phosphate metabolism in every References Melmed S, Koenig R, Rosen C, Auchus R, Goldfine A. Williams textbook of endocrinology: South Asia edition, 2 vol set-E-book. Elsevier India; 2020 Jun 30. Mantovani G, Bastepe M, Monk D, De Sanctis L, Thiele S, Ahmed SF, Bufo R, Choplin T, De Filippo G, Devernois G, Eggermann T. Recommendations for diagnosis and treatment of pseudohypoparathyroidism and related disorders: an updated practical tool for physicians and patients. Hormone research in paediatrics. 2020;93(3):182-96.