Clinical analysis of elven families with mitochondrial encephalomyopathy in children / 中国热带医学

ABSTRACT

@#Abstract Objective To investigate the clinical phenotype and genotype characteristics of mitochondrial encephalomyopathy (ME) families in children. Methods　The clinical data and genetic test results of eleven ME families who were admitted to the department of pediatrics of three tertiary hospitals in Hainan Province from January 2007 to December 2021 were retrospectively analyzed. Results　A total of 13 cases were diagnosed in eleven ME families, including 6 males (46.15%) and 7 females (53.85%). The age of onset ranged from 6 months to 12 years, the interval from onset to diagnosis was 9 months to 8 years and Morava score was 6-11. Clinical symptoms mainly included abnormal movement, developmental retardation or regression, seizures, stroke-like episodes; among the 13 children, 11 (84.62%) had elevated blood lactic acid and 4 (30.77%) had elevated blood creatine kinase. Cranial MRI mainly involved temporal parietal occipital lobe, cerebellum, brainstem and basal ganglia, some with brain atrophy. Gene detection showed that 8 families (72.72%) were caused by mtDNA mutation, of which 5 families and 6 patients were caused by MT-TL1, m.3243A>G, and 5 asymptomatic carriers of 4 families (80.00%) were detected; MT-ND5, m.13513 G>A was detected in 2 families and 3 patients, and an asymptomatic mutation carrier was detected in a family (50.00%); MT-ND3, m.10191T>C was detected in one family and one patient, and 2 asymptomatic mutation carriers were detected. Three families were caused by nDNA mutations (27.27%). A compound heterozygous mutation of c.751C>T and c.516-2A >G in SURF1 gene was found in one family and one patient, which followed autosomal recessive inheritance. The pathogenic loci were inherited from mother and father, respectively. Two new spontaneous mutations c.1040C>G and c.2060_2062delTAG in DNM1L gene were respectively detected in two families and two patients. All children were given mitochondrial cocktail therapy and symptomatic treatment after diagnosis by genetic testing. Follow-up to June 2022, two families were lost to follow-up and 9 families were followed up regularly; three of the 11 children were still survived. Conclusions　For children diagnosed with ME, genetic testing of family members can screen out early asymptomatic pathogenic mutation carriers, achieve early diagnosis of ME and guide clinical genetic counseling. Two new pathogenic sites of DNM1L gene were found in this study, which expanded the genotype spectrum.