Objective To analyze the gene mutation and clinical characteristics of idiopathic dilated cardiomyopathy (DCM) in children.

Methods The results of genetic testing and clinical data of 27 children with DCM treated in the First Affiliated Hospital of Guangxi Medical University from June 2015 to July 2021 were collected. The patients were grouped according to results of genetic testing, the clinical characteristics of the two groups were compared, and the gene mutation and prognosis were explored.

Results There were 27 cases of children with DCM, including 16 cases of male and 11 cases of female, ranging from 0.3 to 13.7 years old, with an average age of (8.5±4.4) years. A total of 13 cases were positive for genetic mutation, accounting for 48.1% (13/ 27). There were no significant differences in the proportion of annual NYHA class Ⅲ/Ⅳ, left ventricular enddiastolic diameter, left ventricular ejection fraction, and mortality between the two groups (P > 0.05). A total of 62 mutation sites were found in 22 kinds of gene mutations in 27 children, among which TTN was 21, accounting for the highest proportion (33.8%). The average follow-up time was (19.3±17.9) months, and 15 cases died, with a mortality rate of 55.5% (15/27). Six cases died in the mutation-positive group, including two cases of TPM1 gene. DMD, DSP, TNNI and TTN genes were found in one case each.

Conclusion The mortality rate is high in children with definite genetic pathogenicity. There is no statistically significant correlation between positive gene mutation and the severity of DCM in children at the first diagnosis as well as the prognosis of children with DCM.