A 34-year-old gentleman with mild dysmorphic features presented to the emergency department with a sudden onset loss of consciousness which lasted approximately 1 minute, during which he sustained tonic-clonic movements which self-terminated. A 1 year history of episodic carpopedal spasms and upper limb paraesthesia was elicited. A head computed tomography (CT) scan was normal. A corrected calcium level was 1.17 mmol/L.
His past medical history included a febrile seizure at 2 years of age, with no history suggestive of absence seizures or myoclonic jerks. He was operated for testicular torsion, acute appendicitis, a congenital epigastric hernia, a supraumbilical hernia, and a removal of an accessory digit in the left hand, the latter of which was also present in relatives from his paternal side. His developmental history included gestation at term with a birth weight of 3.2 kg and a delayed growth spurt. Until the age of 13 years he had regular physiotherapy for recurrent chest and sinus infections, with multiple hospital admissions. At that point he was thoroughly investigated and a diagnosis of cystic fibrosis was suspected, with equivocal sodium sweat tests. Heaf tuberculin skin test (Sterneedle test) in 1985, in spite of previous TB vaccination, was negative. During his adolescence he also reported incapacitating muscle cramps, which later resolved. Learning difficulties were attributed to his frequent absence from school, but the patient was now in full time employment.
On examination there was mild facial dysmorphism with a short philtrum. He was haemodynamically stable, with an early diastolic murmur. Chest was clear. Examination of the neck revealed a grossly enlarged right thyroid lobe, with deviation of the trachea to the left. 
Thyroid function tests and antithyroid antibodies were normal. Serum parathyroid hormone levels were low. Serum calcitonin levels were elevated. Other routine blood investigations, including magnesium levels, were normal. A CT scan of the neck and thorax showed a grossly enlarged, inhomogeneous thyroid gland which was extending deep into the upper mediastinum and associated with enlarged cervical lymph nodes (Figures 1 and 2). An incidental right-sided aortic arch was also noted (Figure 3). In view of the malignant features on CT, a total thyroidectomy and lymphadenectomy was performed. Histopathology reported the presence of two separate follicular adenomata and a nodular goitre.
The patient was discharged on calcium supplements, alpha-calcidol and antiepileptic drugs. The latter were initiated in view of tonic carpo-pedal spasms, which were initially considered to be suggestive of partial seizure activity. A brain magnetic resonance (MR) scan was unremarkable. No further seizures were reported during the follow-up period with continuation of calcium supplementation and the antiepileptic treatment was stopped.
Fluorescence in situ hybridisation (FISH) analysis later confirmed the diagnosis of DiGeorge syndrome with a deletion on the long arm of chromosome 22-22q11.2 deletion.