Conclusions
In this study, we reported two CMT 2O cases carrying DYNC1H1 c.1792C>T/p.R598C and a novel site, DYNC1H1 c.790C>G/p.R264G heterozygous mutations, respectively, clinically manifesting delayed motor milestones, muscle weakness and wasting of lower limbs and normal sensation. By systematically reviewing previous publications, we found that SMA-LED and CMT2O patients caused by DYNC1H1 mutations showed generally similar clinical phenotypes with some differences that may provide references for early diagnosis and differentiation of the two disease entities, such as the differences in the distribution pattern of muscle impairment, sensory system involvement, etc. Our findings also suggested that mutations in the DYN1 region of DYNC1H1 may be correlated with more severe clinical phenotype and more complicated manifestations. In addition, CNS involvement is also more common in such patients. The genotype-phenotype correlation may reflect the pathogenesis underlying dyneinopathy caused byDYNC1H1 mutations.