Delineation of the phenotype associated with 7q36.1q36.2 deletion: long QT syndrome, renal hypoplasia and mental retardation

Abstract

Terminal deletions of the long arm of chromosome 7 are well known and are frequently associated with hypotelorism or holoprosencephaly due to the involvement of the SHH gene located in 7q36.3. These deletions are easily detectable with routine subtelomeric MLPA analysis. Deletions affecting a more proximal part of 7q36, namely bands 7q36.1q36.2 are less common, and may be missed by subtelomeric MLPA analysis. We report a 9-year-old girl with a 5.27 Mb deletion in 7q36.1q36.2, and compare her to literature patients proposing a phenotype characterized by mental retardation, unusual facial features, renal hypoplasia and long QT syndrome due to loss of the KCNH2 gene. These characteristics are sufficiently distinct that the syndrome may be diagnosed on clinical grounds.