An Xp21.3p11.4 duplication observed in a boy with intellectual deficiency and speech delay and his asymptomatic mother.

Background: Interstitial Xp duplications have been rarely described, especially in males. Male patients show intellectual deficiency (ID) and variable congenital malformations depending on the size and the position of the duplication.

Methods: Cytogenetic and molecular analyses using standard G-banding, R-banding, fluorescence in situ hybridization, and an array comparative genomic hybridization analysis for copy number variation detection were performed in the propositus and his mother.

Results: A 12,168,283 bp interstitial duplication of the Xp21.3p11.4 region was detected in the boy with ID and speech delay and his asymptomatic mother.

Conclusion: An Xp21.3p11.4 duplication was characterized at the molecular level in a boy with ID and speech delay. Genotype-phenotype correlations of interstitial Xp duplications were performed by comparing previously reported cases and our patient.