Exons 8 through 13 and 17 mutations according to mastocytosis age of onset.

Data are expressed in number (percentage), 816: substitution of valine in 816 codon of c-kit, Other mutations: mutation in exons 8 through 13. WT: absence of mutation in exons 8 through 13 and 17. Complete genotype was not available for 4 816 WT patients; 1 patient in group 1A, 1 in group 1B and 2 in group 2.