Case of 22q11.2 deletion syndrome not identified by TBX1 screening with a positive SCID newborn screen

Individuals with 22q11.2 deletion syndrome (22q11.2DS) have an embryological midline fusion defect, which can result in a syndrome including congenital heart disease, cleft palate, hypoparathyroidism, thymic hypoplasia, immunologic abnormalities, and developmental delay. The majority of patients have a 3 megabase deletion, which contains multiple genes, including the T-box transcription factor (TBX1) gene. Definitive diagnosis is made through …