Maternally inherited unbalanced translocation of chromosome 22 in a 5-day-old neonate with persistent fifth aortic arch and tetralogy of Fallot

Abstract

Chromosome 22q11 deletion is notoriously famous for its frequent association with conotruncal cardiac malformations and abnormal patterning of the aortic arch [1–4]. We have recently encountered a 5-day-old neonate presenting partial DiGeorge anomaly with high arch palate, hypocalcemia, a narrow cardiac waist reminiscent of hypoplastic thymus, and cardiovascular phenotypes of tetralogy of Fallot, pulmonary atresia, and type III major aortopulmonary collateral artery (MAPCA) from the left subclavian artery. In addition, there is a persistent fifth aortic arch that takes off early as the first branch from the ascending aorta and continues as a left subclavian artery. Cytogenetic analysis of the proband’s blood revealed a derivative chromosome 2 and absence of one chromosome 22 (Fig. 1A). Fluorescence in situ hybridization (FISH) detected her karyotype as 45,XX,der(2)t(2;22)(q37;q12.1),-22 .ish der(2) (TUPLE 1-) (Fig. 1B). Cytogenetic analysis and FISH study of her parents’ blood tracked down the gamete to be maternally inherited (Fig. 1C,D). To the best of our knowledge, this form of maternally inherited unbalanced translocation of chromosome 22 to chromosome 2 has never been reported in patients with conotruncal malformation and/or abnormal patterning of the aortic arch in the English literature.