SAT-070 Nutritional Deficiency of Calcium Mimicking P Seudohypoparathyroidism

BACKGROUND: Childhood hypocalcemia in general is caused by problems associated with calcium absorption and excretion, parathyroid hormone (PTH) secretion, and vitamin D metabolism. Clinical manifestations can vary from asymptomatic hypocalcemia to life-threatening conditions including convulsions, tetany and laryngeal spasm. As many symptoms are nonspecific, laboratory tests are essential for diagnosis. Nevertheless, the causes of hypocalcemia may not be determined by simple interpretation of baseline calcium, phosphorus, alkaline phosphatase (ALP), PTH and calcidiol (25OHD). Case presentation: We report a case of 11-month-old female with a generalized tonic type seizure with low serum calcium level (5.7 mg/dl), 25OHD (23.2 ng/mL) and calcitriol (1,25OH2D) (12.83 pg/mL). Serum phosphorus (5.9 mg/dL), ALP (209 mg/dL) were above normal range and PTH (484 pg/mL) was markedly elevated. She had a problem with weaning process after age of 5 months and milk powder was her main staple diet. Pseudohypoparathyroidism (PHP) was suspected due to slightly increased serum phosphorus, however Albright’s hereditary osteodystrophy manifestation was absent and no GNAS methylation defect was identified. Serum calcium was normalized by intravenous calcium-gluconate followed by oral calcium carbonate and vitamin D supplement. Two months of oral oral calcium carbonate and vitamin D supplementation alone normalized all laboratory results. Conclusions: Severe nutritional deficiency of calcium could mimic laboratory findings of PHP, therefore clinical judgement should not be made solely on biochemical markers. Keywords: Hypocalcemia, pseudohypoparathyroidism, rickets 제1저자: Yoonji Lee, Moonbae Ahn, Na yeong Lee, Seonhwa Lee, Yujung Choi, Seulki Kim, Shinhee Kim, Wonkyoung Cho, Kyoungsoon Cho, Minho Jung, and Byungkyu Suh* Department of Pediatrics, College of Medicine, Catholic University of Korea