A de novo 2.3 Mb deletion in 2q24.2q24.3 in a 20-month-old developmentally delayed girl

We report a 20-month-old girl ascertained at the age of 11 months for developmental delay. She presented with hypotonia and delayed motor development. The patient had severe language impairment and showed behaviour consistent with autism spectrum disorder. She was microcephalic with mild dysmorphic features and had joint hyperlaxity. We detected a 2.3 Mb de novo deletion in 2q24.2q24.3 on her paternal chromosome. We compare the clinical features of our patient to six previously published patients with a deletion in 2q24.2q24.3, and one patient reported in the ECARUCA database. Although the clinical presentation of these patients is not highly consistent, likely due to the different deletion size and gene content, the following features seem to be recurrent: disturbance in the central nervous system, poor growth, hypotonia, and joint hyperlaxity. The region deleted in our patient contains 13 genes including PSMD14, TBR1, SLC4A10, DPP4, KCNH7, and FIGN. We briefly review the knowledge of these genes and their possible involvement in the aetiology of this developmental delay syndrome.