4th April 2024

DiGeorge syndrome

Di George syndrome is an autosomal dominant syndrome caused by a deletion in chromosome 22 (22q11.2). Nearly two-thirds of children with Di George syndrome present with hypocalcaemia in the neonatal period, characterised by jitteriness, tetany, or seizures. This is caused by underdevelopment of the parathyroid glands. Patients may also be identified during the neonatal period due to congenital heart defects, such as tetralogy of Fallot, atrial or ventricular septal defects or truncus arteriosus. Children classically present with a triad of cardiac anomalies, hypoplastic thymus and hypocalcaemia.

However, some children do not present with such overt symptoms and, therefore, may be diagnosed later in life due to delayed development, failure to thrive or frequent infections. An absent or hypoplastic thymus gland, resulting in T cell deficiency, may lead to recurrent sinopulmonary infections or viral infections. Developmental delay occurs in most patients with DGS, with many children experiencing speech delay, in part due to palatal abnormalities such as cleft palates.

Investigations

Di George syndrome is diagnosed based on reduced CD3+ T cells, together with characteristic clinical findings (as described above) or detected deletion of chromosome 22q11.2.

Management 

Acute management in neonates centres around management of hypocalcaemia and surgical correction of significant congenital cardiac defects. Feeding and swallowing problems due to palatal or gastrointestinal defects may be critical issues in the first few days of life. Those with complete athymia are unlikely to survive beyond the first few years of life.