Chromosome 15q13 microduplication in a fetus with cardiac rhabdomyoma: a case report

Copy number variation (CNV) is a complex genomic rearrangement that has been linked to a large number of human diseases. Chromosome 15q13 microduplication is a rare form of CNV, which has been proved to be associated with multiple human disorders; however, the association between chromosome 15q13 microduplication and cardiac disorders has not been fully understood.

A fetus with fetal cardiac developmental defects was detected by Color Doppler ultrasound imaging; however, further chromosomal G-banding revealed no abnormal karyotype. Then, chromosomal microarray analysis (CMA) was performed and revealed a 1.8 Mb-duplication of the chromosome 15q13.2q13.3 region containing 7 genes (TRPM1, KLF13, OTUD7A, CHRNA7, FAN1, MIR211 and RAHGAP11A). Cardiac ultrasound follow-up displayed significant enlargement of the space-occupying lesion in the fetal heart with extension of the gestational age, and the space-occupying lesion was finally pathologically diagnosed as cardiac rhabdomyoma. Next-generation sequencing revealed no mutations in the TSC1 or TSC2 gene in the fetus, the mother or the father.

This is the first report to demonstrate the potential association between chromosome 15q13 microduplication and fetal cardiac rhabdomyoma. It is recommended that CMA be employed in fetuses with abnormal cardiac development diagnosed by routine cardiac color Doppler ultrasound imaging for early detection of congenital genetic abnormality, which may provide valuable information for prenatal diagnostic consultation and the decision on pregnancy termination.