Genetic results and clinical outcome of fetuses with cardiac rhabdomyoma including a novel mutation in TSC2 gene

Background: Cardiac rhabdomyoma is the most common type of the fetal cardiac tumors which are rare diseases. The prognosis of cardiac rhabdomyoma(s) is closely related to quality of themselves and whether affected by tuberous sclerosis. This study was aimed to determine the clinical value of combining ultrasound and detection of the TSC gene when assessing the prognosis of cardiac rhabdomyoma in the fetus. Methods: This retrospective study presented 24 fetuses with cardiac rhabdomyoma(s) diagnosed prenatally with fetal echocardiography in our hospital from June 2018 to May 2024. Multiplex ligation-dependent probe amplification (MLPA) and next-generation sequencing (NGS) for TSC genetic testing were offered. The genetic consultation was provided for all pregnant women with fetal cardiac rhabdomyoma, and the clinical outcomes were followed up. Results: Among the 24 cases of cardiac rhabdomyoma, 14 cases (58.3%) were single, 10 cases (41.6%) were multiple, and the most common location was left ventricle (29.2%), followed by right ventricle (25%). TSC genetic testing was found abnormal in 54.2% (13/24) of the fetuses; the fetus was born alive in 10 cases and the pregnancy was terminated in 14 cases. One novel mutation, c.3728delA in TSC2 gene, hasn't been reported in the previous studies. Conclusions: MLPA and NGS are effective methods to detect mutations of TSC1/TSC2 for prenatal diagnosis. The prognosis of fetuses with simple cardiac rhabdomyoma is good. Our practice provides a practical and feasible advice for genetic counseling for fetuses with CR.