PSAT183 Severe Hypocalcemia Precipitated by COVID-19 Infection in a Patient with Albright Hereditary Osteodystrophy and Pseudohypoparathyroidism

BACKGROUND: Hypocalcemia is a common endocrine manifestation of COVID 19 infection. We present a rare case of severe hypocalcemia in a patient with a history of Pseudohypoparathyroidism (PHP) type 1A after COVID-19 infection. PHP is a genetic disorder that presents with hypocalcemia, hyperphosphatemia, and secondary hyperparathyroidism due to marked target-organ unresponsiveness to parathyroid hormone (PTH). PHP type 1A also has a characteristic somatic phenotype known as Albright Hereditary Osteodystrophy (AHO), including short stature, brachydactyly, shortened metatarsals, and often reduced intelligence. CASE PRESENTATION: This is a 53-year-old female with PHP type 1A, diabetes mellitus type 2, hypothyroidism, vitamin D deficiency, mild intellectual disability, and hypertension. She presented with new onset of seizures. She was also found to be positive for COVID-19 infection. On Review of systems, she had diarrhea but denied perioral or extremity paresthesia, palpitations, muscle spasms and bone pain. She reported compliance with calcitriol and calcium supplements at home. She had short stature, round face, short neck, obesity, brachydactyly (short digits of right 4th and 5th fingers) and shortened left 4th metacarpal. Labs revealed corrected serum calcium from baseline of 7.8 mg/dL to 4.4 mg/dL, ionized calcium 2.9 mg/dL, vitamin D 12.8ng/ml, PTH 142pg/ml and phosphorus 6.2mg/dl. EKG showed T wave inversions and prolonged QT interval. She did not have tetany, carpopedal spasm, paresthesia, Chvostek's sign, or Trousseau's sign. After receiving a total of 11 grams of elemental calcium, calcitriol, and ergocalciferol, her corrected calcium level improved to 7.4 mg/dL and EKG normalized. She was discharged home with calcium carbonate 1,250 mg twice a day and calcitriol 0.5 mcg daily. DISCUSSION: PHP type 1A is an autosomal dominant mutation of the stimulatory G protein alpha subunit (G alpha or GNAS) derived from the mother due to genomic imprinting which leads to PTH resistance in the kidneys and parathyroid glands. Our patient had a long-standing history of mild hypocalcemia with calcium and calcitriol supplements. Sudden worsening of hypocalcemia was likely related poor calcium and calcitriol absorption induced by COVID-19 infection. Patient with chronic hypocalcemia may not present with typical hypocalcemia signs or symptoms due to their tolerance. CONCLUSION: Clinicians should be aware of the risk of developing severe hypocalcemia in patients who are calcium dependent or vitamin D deficient, malnourished during critical illness, or have COVID-19 infection which may decrease serum albumin and reduce total serum calcium level. Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m.