Prenatal diagnosis of a 5q35.3 microduplication involving part of the ADAMTS2 locus: a likely benign variant without apparent phenotypic abnormality: Case series

RATIONALE: Chromosomal duplications are associated with a series of genetic disorders. However, chromosome 5q duplications, especially pure 5q35.3 microduplications, have rarely been reported in the literature. Clinical phenotypes usually depend on the region of chromosome duplicated, its size, and loci. PATIENT CONCERNS: From 2011 to 2017, prenatal amniotic fluid samples were obtained from 6 pregnant women diagnosed with pure 5q35.3 microduplications following different prenatal indications at our center. We followed up the children of these pregnancies and determined their postnatal health conditions. DIAGNOSES: Cytogenetic studies delineated that all patients had normal karyotypes, except for patient 6 who had 46,XX,inv(9)(p11q13). Single-nucleotide polymorphism array results showed 177–269 kb duplications of 5q35.3 (chr5:178728830–178997692) in these cases. All shared similar localization of ADAMTS2. INTERVENTIONS: All pregnant women chose to continue the pregnancies. Follow-up analysis showed that the children presented normal physical and growth developments. OUTCOMES: We described six prenatal cases with similar 5q35.3 duplications involving part of the ADAMTS2 locus with no apparent postnatal phenotypic abnormalities. LESSONS: Our research revealed that partial microduplication of ADAMTS2 (chr5:178728830–178997692) might be benign and not correlate with disorders. And there might exist phenotypic diversities of 5q35.3 duplications.