Molecular Genetic Analysis and Prenatal Diagnosis of a Family With MECP2 Duplication Syndrome.

OBJECTIVE

This study aimed to conduct a molecular genetic analysis and prenatal diagnosis for a family with MECP2 duplication syndrome (MDS), with the goal of improving diagnostic accuracy and enabling informed reproductive decisions to reduce the incidence of this condition.

METHODS

The study involved a proband (a 15-week-old fetus), his symptomatic older brother, and their parents. Genomic DNA from chorionic villus and peripheral blood samples was analyzed using high-throughput sequencing to detect chromosomal copy number variations (CNVs). To confirm the findings, multiplex ligation-dependent probe amplification (MLPA) was specifically employed.

RESULTS

High-throughput sequencing identified a 0.35 Mb duplication at Xq28 in the fetus and his mother, and a 0.4 Mb duplication in the brother. The duplicated region contained the critical MECP2 gene. MLPA analysis confirmed the MECP2 gene duplication in the fetus, leading to a definitive diagnosis of MDS. The mother was identified as an asymptomatic carrier.

CONCLUSION

Both the proband and his brother were diagnosed with MDS, having inherited the duplication from their asymptomatic mother. The combined use of high-throughput sequencing and MLPA proved to be an effective strategy for accurate pedigree analysis and prenatal diagnosis of MDS, providing a crucial basis for genetic counseling.