A Unique Phenotype of 2q24.3–2q32.1 Duplication: Early Infantile Epileptic Encephalopathy Without Mesomelic Dysplasia. (February 2014)

• Record Type: Journal Article
• Authors: Lim, Byung Chan; Min, Byung-Joo; Park, Woong-Yang; Oh, Sun Kyung; Woo, Mi Jung; Choi, Jin Sun; Kim, Ki Joong; Hwang, Yong Seung; Chae, Jong Hee
• Is Part Of: Journal of child neurology. Volume 29:Number 2(2014:Feb.)
• Page Start: 260
• Page End: 264
• Publication Date: 2014-02
• Subjects: 2q duplication -- comparative genomic hybridization array -- mesomelic dysplasia -- epilepsy -- hypoplastic left heart syndrome -- sodium channel -- HOXD; Nervous system -- Diseases -- Periodicals; 618.928
• DOI: 10.1177/0883073813478659
• Languages: English
• ISSNs: 0883-0738

Abstract

The voltage-gated sodium channel genes and HOXD genes are clustered on chromosome 2q, and duplication of this region is associated with 2 clinical phenotypes: early-onset epilepsy and mesomelic dysplasia Kantaputra type, respectively. We report a case involving 2q24.3–2q32.1 duplication encompassing both the voltage-gated sodium channel and HOXD gene clusters, which were detected by a comparative genomic hybridization array. The associated clinical features were early-infantile-onset epilepsy, hypoplastic left heart syndrome, and global developmental delay. However, no features of mesomelic dysplasia were found. A fluorescent in situ hybridization study showed that the noncontiguous insertion of the duplicated chromosome 2q segment into chromosome 6q was inherited from the father, who has a balanced insertional translocation. The unique genotype–phenotype correlation in the present case suggests that dosage-sensitive effects might apply only to the voltage-gated sodium channel genes.