A 29 year old female presented with a two year history of recurrent numbness and tingling in her hands. Trousseaus sign was positive. Investigations confirmed hypocalcaemia with serum calcium 1.64 nmol/L (2.102.60), phosphate 1.23 nmol/L (0.801.55), alkaline phosphatase 82 U/L (35120). Parathyroid hormone was inappropriately normal at 36 pg/ml (1065), Vitamin D 78 nmol/L (5075). Her mother reported a history of hypocalcaemia when she was two days old, which responded to calcium and vitamin D supplementation. Velopharyngeal incompetence was present during childhood which subsequently improved over time. The patient had learning difficulties but was now in full time employment.
The presence of hypoparathyroidism in association with a history of transient neonatal hypocalcaemia and velopharyngeal incompetence during childhood prompted chromosomal analysis for Di-George syndrome. Fluorescent hybridisation in situ revealed deletion of chromosome 22q11.2.
There was no history of recurrent infections and immunological testing demonstrated normal CD4 and CD8 counts. Echocardiography revealed no cardiac or aortic arch abnormalities. Renal ultrasound was normal.
The patient was informed of the diagnosis and commenced on treatment with vitamin D and calcium supplementation. She has been referred for genetic counselling along with other family members.
Di-George syndrome is associated with developmental abnormalities of the third and fourth pharyngeal pouches. Hypoplasia of the thymus and parathyroids, aortic arch and facial malformations and learning difficulties are common. The majority of cases are sporadic and associated with submicroscopic deletions of chromosome 22q11. Hypocalcaemia generally improves over the first year as the parathyroid glands hypertrophy. Di-George syndrome presenting as hypocalcaemia in adulthood is rare. This case is unusual in that the patient remained asymptomatic apart from speech and language delay after the first few months of life and presented in adulthood without any associated immunological, cardiac or renal abnormalities. The diagnosis has important implications for health and family planning.