Chromosome 13q deletion syndrome involving 13q31­qter: A case report.

Partial deletions on the long arm of chromosome 13 lead to a number of different phenotypes depending on the size and position of the deleted region. The present study investigated 2 patients with 13q terminal (13qter) deletion syndrome, which manifested as anal atresia with rectoperineal fistula, complex type congenital heart disease, esophageal hiatus hernia with gastroesophageal reflux, facial anomalies and developmental and mental retardation. Array comparative genomic hybridization identified 2 regions of deletion on chromosome 13q31­qter; 20.38 Mb in 13q31.3­qter and 12.99 Mb in 13q33.1­qter in patients 1 and 2, respectively. Comparisons between the results observed in the present study and those obtained from patients in previous studies indicate that the gene encoding ephrin B2 (EFNB2) located in the 13q33.3­q34 region, and the gene coding for endothelin receptor type B, in the 13q22.1­31.3 region, may be suitable candidate genes for the observed urogenital/anorectal anomalies. In addition, the microRNA­17­92a­1 cluster host gene and the glypican 6 gene in the 13q31.3 region, as well as EFNB2 and the collagen type IV a1 chain (COL4A1) and COL4A2 genes in the 13q33.1­q34 region may together contribute to cardiovascular disease development. It is therefore possible that these genes may be involved in the pathogenesis of complex type congenital heart disease in patients with 13q deletion syndrome.