Furthermore, the implication of decreased relative Δ7SMN mRNA levels in the absence of changes in flSMN would be to increase the ratio of flSMN to SMNΔ7, the major discriminator between SMA subjects and unaffected controls/carriers when using relative measures of SMN mRNA, suggesting that these changes could be important. The gene discussed is SMN2; the disease is proximal spinal muscular atrophy.