ABSTRACT Aim To characterise spinal muscular atrophy (SMA) phenotypes, genetic profiles, and nusinersen efficacy in China. Methods In 133 SMA patients (age 6.38 ± 3.66 years), SMN1 mutations and SMN2 copy numbers were analysed by MLPA and sequencing. Motor function was longitudinally assessed using subtype‐specific scales (CHOP‐INTEND/HFMSE/RULM/6MWT) at baseline, 6, and 12 months post‐nusinersen. Results Cohort distribution: type I 31.6% (42/133), II 42.1% (56/133), III 26.3% (35/133). Genetic profiling identified: SMN1 exon7 + 8 deletions (81.2%, 108/133); exon7‐only deletions (15.0%, 20/133); and a novel c.884A>T; c.22dup mutation (0.8%). SMN2 copy number inversely correlated with clinical severity ( p T; c.22dup).
Gan et al. (Tue,) studied this question.