In the Spanish cohort (n = 28), patients >18 months at diagnosis with an SCA profile, partly combined with SCA heterogeneity, prevailed.26 In the Austrian cohort (n = 26), age <18 months at diagnosis was clearly associated with wcUPDs (especially for chromosome 11); age >18 months, however, was associated with a multitude of SCAs and occurrence of intragenic ATRX deletions.28 The genetic findings of both studies corroborate the differences in the genetic ‘background’ between hetMNA and homMNA tumours, but the implications of MNA heterogeneity for the treatment remain to be solved. This evidence concerns the gene ATRX and autosomal dominant cerebellar ataxia.