Italian clinicians investigated new predictive factors for the evolution of SMA according to age, type of SMA and gender in 165 adult patients.
- There were 64 females and 101 males: 13% with type II, 85% with type III and 2% with type IV SMA and with 46% able to sit (sitters) and 54% able to walk (walkers).
- No significant differences were reported between the two sexes for the distribution of SMA type or for the median SMN2 copy number.
- For the first time, an effect of gender on motor function was found in these adults with the HFMSE, RULM and 6-minute walk test: a higher severity of the disease was found in males, especially in young adults or those with type III SMA.
- Concerning the median age of disease onset, it is earlier in women (at age 3) than in men (at age 4).