Late-onset cblC-type methylmalonic aciduria with homocysteinemia：A case report and literature review / 中风与神经疾病杂志

ABSTRACT

@#Objective To investigate the clinical characteristics and gene mutations of late-onset methylmalonic aciduria with homocysteinemia. Methods We retrospectively analyzed the clinical data and genetic test result of one patient with late-onset cblC-type methylmalonic aciduria with homocysteinemia arising from MMACHC gene mutation. Relevant literature was reviewed. Results This male patient initially presented with numbness in both feet, and gradually developed stiffness and weakness in both lower limbs, with nonspecific mental and behavioral symptoms before onset. Gene testing detected a missense mutation, c.482G>A（p.Arg161Gln） in exon 4 of the MMACHC gene. It was a homozygous mutation, which was different from compound heterozygous mutations of c.482G>A reported in previous literature. Conclusion Methylmalonic aciduria with homocysteinemia is clinically heterogeneous, with a high possibility of a missed diagnosis or misdiagnosis. The diagnosis should be considered in the presence of mental and behavioral abnormities of unknown cause. Gene detection is an important basis for the diagnosis and typing of the disease.