A unique phenotype of 2q24.3-2q32.1 duplication: early infantile epileptic encephalopathy without mesomelic dysplasia.

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.

• Authors: Byung Chan Lim, Byung-Joo Min, Woong-Yang Park, Sun Kyung Oh, Mi Jung Woo, Jin Sun Choi, Ki Joong Kim, Yong Seung Hwang, Jong Hee Chae
• Journal: Journal of child neurology (J Child Neurol) Vol. 29 Issue 2 Pg. 260-4 (Feb 2014) ISSN: 1708-8283 [Electronic] United States
• PMID: 23456534 (Publication Type: Case Reports, Journal Article, Research Support, Non-U.S. Gov't)

Topics

• Aicardi Syndrome (genetics, physiopathology)
• Brain (physiopathology)
• Chromosomes, Human, Pair 2 (genetics)
• Comparative Genomic Hybridization
• Developmental Disabilities (genetics, physiopathology)
• Electroencephalography
• Fathers
• Humans
• Hypoplastic Left Heart Syndrome (genetics, physiopathology)
• In Situ Hybridization, Fluorescence
• Infant
• Male
• Phenotype
• Spasms, Infantile (genetics, physiopathology)
• Translocation, Genetic
• Trisomy (genetics, physiopathology)