Genealogic tree of a large and complex family with MPD. Filled symbols indicate patients with MPD. Affected patients are numbered from 1 to 5. The type of MPD is reported on the first line under each symbol. The age at diagnosis and age at inclusion into the study (or at death in parentheses) are indicated on the second and third line, respectively. On the fourth line, the JAK2 genotype followed by the proportion, in percent, of mutant T allele is reported. - indicates not applicable; Ma, systemic mastocytosis; GG, wild-type JAK2 genotype; GT, heterozygous JAK2 genotype.