It must be noted that the median age of CMT1A patients (59 years ± 20 years S.D.)was higher than that of controls (48 years ± 17 years), and the levels of NFL correlated significantly with the age in individuals with CMT1A (Fig. 3F) but not in controls (Fig. 3G). Here, PMP22 is linked to Charcot-Marie-Tooth disease type 1A.