A case report of a patient with interstitial duplication of 10p12.1 and 15q11.2q13.1

Abstract

Objective: 15q duplication syndrome is caused by one extra copy of Prader-Willi/Angelman critical region within chromosome 15q11.2q13.1. Compared to 15q duplication syndrome, there are no reported cases of 10p12.1 interstitial duplication. Here, we present a case with interstitial duplication of 10p12.1 and 15q11.2q13.1, together. Methods: 3 months-old male patient presented with decreased tone with poor head control. He started physical therapy, but he could not walk by the age of 17 months. Brain magnetic resonance imaging showed unremarkable finding. Sleep electroencephalogram showed activity consistent with partial seizures. He was referred to the genetic clinic, and chromosome analysis revealed 46, XY at the 550 band level. Array comparative genomic hybridization (CGH) revealed interstitial duplication of 10p12.1 and 15q11.2q13.1, together. The duplication of chromosome 10 was estimated to be 0.8Mb and contained about 5 known genes. The duplication of chromosome 15 was calculated to be 5.7Mb, including 18 known genes. Results: This is the first case report of interstitial duplication at both 10p12.1 and 15q11.2q13.1, together. By searching Developmental Disorders Genotype- Phenotype Database (DDG2P), we found that 2 genes (ARMC4, RAB18) were related with chromosome 10, and 3 genes (GABRB3, MAGEL2, UBE3A) were related with chromosome 15. The phenotype of hypotonia, delayed development, cognitive impairment are all related with previously known 15q duplication syndrome features. However, RAB18 gene at 10p12.1 is also related with mental retardation and hypotonia. Conclusion: Further cumulative data are needed to understand the role and influence of the genes in interstitial duplication of 10p12.1 and 15q11.2q13.1, together.