Specific behavioural phenotype and secondary cognitive decline as a result of an 8.6 Mb deletion of 2q32.2q33.1

Abstract

Chromosomal abnormalities involving 2q32q33 deletions are very rare and present with a specific phenotype. This case report describes a 37-year-old female patient with 2q32q33 microdeletion syndrome presenting with the characteristic features, but with the addition of secondary cognitive decline. Molecular karyotyping was performed on the patient and her parents. It revealed an 8.6 megabase deletion with the proximal breakpoint in the chromosome band 2q32.2 and the distal breakpoint in 2q33.1. The deletion encompassed 22 known genes, including the GLS, MYO1B, TMEFF2, PGAP1 and SATB2 genes. The observed deletion was confirmed using a paralogue ratio test. This case report provides further evidence that the SATB2 gene, together with GLS, MYO1B, TMEFF2 and possibly PGAP1, is a crucial gene in 2q32q33 microdeletion syndrome. The SATB2 gene seems to be crucial for the behavioural problems noted in our case, but deletion of the GLS, MYO1B and TMEFF2 genes presumably contributed to the more complex behavioural characteristics observed. Our patient is also, to our knowledge, the only patient with 2q32q33 microdeletion syndrome with secondary cognitive decline.