Predicting 22q11.2 deletion syndrome: A novel method using the routine full blood count

MPV is a useful screening test, involving no extra laboratory work, cost or patient discomfort. MPV > 10 fL is a positive predictor of the presence of 22q11.2 deletion in children with congenital heart disease (specificity 89.7%). This finding should aid rapid decision-making for ordering irradiated blood products to prevent potentially fatal transfusion-associated graft versus host disease. It will alert clinicians to monitor serum calcium levels closely to prevent hypocalcaemic seizures.