Prenatal diagnosis of de novo int22h1/int22h2-mediated Xq28 duplication syndrome involving RAB39B following a previous ambiguous genitalia pregnancy

Abstract

Objective: To report a prenatal diagnosis of int22h1/int22h2-mediated Xq28 duplication syndrome.

Case report: Herein, we present the case of a 28-year-old female who had a previous ambiguous genitalia pregnancy without genetic abnormality that was terminated at 23⁺² weeks of gestation. The fetus of the current pregnancy harbored a de novo copy number variation at the Xq recurrent region (int22h1/int22h2-flanked; including the RAB39B gene) with a 0.397 Mb microduplication. The literature suggests the clinical manifestation of int22h1/int22h2-mediated Xq28 duplication syndrome tends to show a milder clinical phenotype in females than males. Although the fetus in this case was female, taking into consideration the parents' age and culture, the family decided to terminate this pregnancy due to the genetic abnormality.

Conclusion: Prenatally diagnosed de novo int22h-1/int22h-2-mediated Xq28 duplication syndrome exhibits variable phenotypic traits in female fetuses.

Keywords: Microduplication; X-linked intellectual disability; Xq28 duplication syndrome.