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 theGLS,MYO1B,TMEFF2,PGAP1andSATB2genes. The observed deletion was confirmed using a paralogue ratio test. This case report provides further evidence that theSATB2gene, together withGLS,MYO1B,TMEFF2and possiblyPGAP1,is a crucial gene in 2q32q33 microdeletion syndrome. TheSATB2gene seems to be crucial for the behavioural problems noted in our case, but deletion of theGLS,MYO1BandTMEFF2genes 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.

Keywords: 2q32q33 microdeletion syndrome; SATB2 gene; behavioural problems; developmental delay; secondary cognitive decline.

Figure 1.

Current appearance of a 37-year-old woman with a de novo 8.6 megabase deletion of 2q32.2q33.1 who presented with the characteristic phenotype and behavioural problems, but who also experienced prominent secondary cognitive decline. Characteristic features of 2q32q33 microdeletion syndrome noted in this patient are the sparse hair, thin, pale skin and craniofacial dysmorphism (including long and asymmetric face, short and flat philtrum, pointed chin, oligodontia, and periorbital dermoid cyst). The colour version of this figure is available at: http://imr.sagepub.com.

Figure 2.

A schematic presentation of deletions in patients with reported 2q32q33 microdeletion syndrome and behavioural problems, including those of the present case (labelled red). Size and positions of deletions with implicated genes are presented in the University of California, Santa Cruz Genome Browser. The colour version of this figure is available at: http://imr.sagepub.com.