Introduction: A 22q11.2 deletion syndrome (velocardiofacial syndrome) is an autosomal dominant disorder affects various organs including the parathyroid gland. Because of its incomplete penetrance, multi-system affectation, and variable clinical presentation, the diagnosis is often delayed or never made. Delayed diagnosis may have significant impact on morbidity and mortality. We present a patient with a long history of clinical features of a syndrome which was diagnosed after a delay of many years.
Case: A 46-year-old man presented to the Emergency Department following a seizure. He had a low serum calcium level of 1.94 mmol/l. After treatment he was lost to follow-up and re-presented four years later with a further seizure. His serum calcium level was 1.98 mmol/l. He was prescribed calcium-vitamin D preparation and referred to the Endocrinology team. History taking elicited occasional seizures in childhood with no formal diagnosis of epilepsy. He had undergone a cleft palate repair as a child and had mild learning difficulties. On examination he had low-set ears and a scar indicating previous cleft palate repair. Further investigations revealed an inappropriately low serum parathyroid hormone level of 1.4 pmol/l with normal vitamin D levels in the presence of hypocalcaemia. His clinical presentation led us to suspect a genetic mutation so he was referred to the medical geneticist for further evaluation. Micro-array studies confirmed a micro-deletion on the long arm of chromosome 22. Subsequent echocardiogram demonstrated a dilated aortic root await cardiac MRI. An audiometry revealed sensory neuronal deafness.
Conclusion: Hypocalcaemia in the young especially with phenotypic dimorphism should be addressed with increased diligence. We should have a low threshold for referral to medical genetics as they will require multidisciplinary team input and regular follow-up once a genetic diagnosis is established.