Endocrine Abstracts

Introduction: We present a rare cause of hypoparathyroidism and hypocalcemia and implications of the same during pregnancy.

Case report: A 22-year-old primigravida was referred to the antenatal endocrine clinic with a longstanding history of hypoparathyroidism with hypocalcaemia. She had short stature and extended digits relative to her height. She has been taking alfacalcidol 0.5 μg once a day and adcal D3 tablets and blood tests revealed low normal calcium and PTH levels. Her 20 weeks antenatal scan showed foetal cardiac abnormalities severe enough to consider medical termination of pregnancy. Post mortem examination of the foetus confirmed a baby girl with truncus arteriosus and a ventricular septal defect. Genetic studies of the foetus showed karyotype of 46XX, with a microarray analysis identifying a micro-deletion at 22Q11.21 consistent with DiGeorge/velocardiofacial syndrome. Further genetic tests performed on the patient and spouse confirmed that she was a heterozygous carrier with the same micro-deletion compatible with DiGeorge syndrome and her spouse had no chromosomal abnormalities. A subsequent echocardiogram of the patient demonstrated no significant cardiac abnormalities.

Conclusion: DiGeorge syndrome or 22q11.2 deletion syndrome is a rare disorder caused by micro-deletion of a small piece of chromosome 22 normally manifesting with thymic aplasia (causing immune deficiency), hypocalcemia, hypoparathyroidism, congenital heart defects, and palatal cleft defects. The micro-deletion occurs near the middle of the chromosome at the loci q11.2. This condition should be considered in the differential diagnosis of hypoparathyroidism on its own as it has different levels of penetrance and can have implications when considering pregnancy