ESPE Abstracts

Introduction: Pseudohypoparathyroidism (PHP) is a group of heterogenous disorders characterized by end organ resistance to parathyroid hormone (PTH) action. In 1942, Fuller Albright first described the phenotype of Albright Hereditary Osteodystrophy (AHO) associated with end organ hormone resistance (brachydactyly, rounded face, short stature, central obesity, subcutaneous ossifications, and variable degrees of mental retardation). Recently EuroPHP network proposed new classifications of PHP to minimize confusion and simplify this rare disease. Molecular defects affecting the PTH/PTH- related Peptide signalling disorders have been described.

Case report: : YG, currently 22 years old, presented at the age of 12 with hypocalcaemic seizures. Bone profile showed corrected calcium: 1.18 mmol/l, phosphate: 2.6 mmol/l and serum PTH: 181.3 pg/ml (15-65 pg/ml). The 25-hydroxy vitamin D level was 18.46ng/ml (20-32 ng/ml), which was easily corrected. She was started on oral calcium carbonate 750mg TDS and T. alfacalcidol 1mcg OD. Clinical examination revealed a short and thin girl, weight: 23.7kg (below 3^rdpercentile) and height: 129cm (below 3^rd percentile). Normotensive, no goitre. No other features of Albright hereditary osteodystrophy. YG was born term with birth weight of 3.2kg. She was exclusively breastfed till 3 months old before the introduction of formula milk. Normal developmental milestone and an average student at school. At 15 years old, she was noted to have asymptomatic hypokalaemia and hypomagnesemia needing replacement. Potassium: 2.8-3.2 mmol/l, Magnesium: 0.6-0.7 mmol/l. Urine potassium: 52 mmol/l. No metabolic alkalosis/acidosis and no hypocalciuria. Renin: 54.2 mU/L (N: 4.2-59.7), Aldosterone: 660.9 pmol/l (N: 102.5- 1196.6). Unfortunately, throughout the years, she developed small speck of cataract of right eye with normal visual acuity. Her annual ultrasound kidney, ureter and bladder did not detect any nephrocalcinosis. She attained menarche at 15 years old. She was diagnosed with epilepsy at the age of 18 and was commenced on lamotrigine and levetiracetam. There were multifocal brain parenchymal calcifications in her CECT brain and generalised atypical spike wave discharges consistent with structural (symptomatic) epilepsy seen in her EEG.

Discussion and conclusion: YG, a young lady with pseudohypoparathyroidism associated with persistent hypokalaemia and hypomagnesemia not fulfilling either Bartter or Gitelman syndrome as the cause of her tubulopathy. Only 2 case reports mentioned pseudohypoparathyroidism type 1b associated with Bartter like syndrome have been reported. YG is awaiting her genetic review for molecular diagnosis. Whether these abnormalities are associated with her PHP or a different entity is yet to be determined.