DiGeorge syndrome: clinical variability in a family with submicroscopic deletion at 22q11.2

DiGeorge syndrome is a developmental field defect involving the third and fourth branchial arches and pouches. It is characterised by conotruncal heart defect, thymic hypoplasia/aplasia, hypocalcemia secondary to hypoparathyroidism and dysmorphic facies. Most of the cases are associated with interstitial deletion of chromosome 22 which can be detected by fluorescent in situ hybridisation study. The clinical presentation of DiGeorge syndrome is highly variable, in both interfamilial and intrafamilial situations. Apart from DiGeorge syndrome, velocardiofacial syndrome and other conditions are also associated with the same interstitial deletion. Here we reported a Chinese family with the same submicroscopic deletion of chromosome 22 as evident by fluorescent in situ hybridisation, but with different clinical presentation; the two brothers had DiGeorge syndrome and velocardiofacial syndrome respectively whereas the mother was asymptomatic.