Echocardiographic diagnosis and genotyping of antenatal cardiac rhabdomyoma

Objective To analyze the echocardiographic features of antenatal cardiac rhabdomyoma, and the significance of genotyping in tuberous sclerosis complex (TSC). Methods From January 2013 to September 2015, 10 out of 7 559 fetal cases tested in the Maternal-Fetal Medical Center for Fetal Heart Diseases, Anzhen Hospital who were suspected of cardiac rhabdomyoma, with biological specimens, were enrolled in the analysis. Heart tissue, umbilical cord, deltoid or other tissues were collected from eight fetuses of terminated pregnancy, and peripheral blood was collected from the two newborns and their parents. Next generation sequencing using target area capture technology was performed to sequence TSC1 and TSC2 gene exon intron and its adjacent 10 bp, and Sanger sequence was confirmed in parents. Results Among the 10 fetuses, four were familial and the other six were sporadic cases. Echocardiography revealed a single tumor in two fetuses, and multiple tumors in eight fetuses. No mutation of TSC1 or TSC2 gene was detected in the two fetuses with isolated tumors, while mutations were found in the other eight fetuses, including two cases of known mutations and both were familial, four cases of new suspected mutations (two were familial), one with unknown clinical significance and one was suspected of benign variation. Conclusions Most prenatal cardiac tumors detected by echocardiography are TSC, and often manifested as multiple solid nodules. Pathogenic or suspected pathogenic gene mutations are more common in familial diseases. Key words: Heart neoplasms; Rhabdomyoma; Echocardiography; Ultrasonography, prenatal; Genetic testing