Pedigrees and DNA sequences of the 2 families with germ line LNK (E208Q) mutation. Filled symbols represent affected patients. The diagnosis (PV or ET) and the JAK2 (V617F) allele burden are reported below each symbol. DNA sequences of granulocytes (polymorphonuclear cells [PMN]), T lymphocytes (T-Ly), and hair roots, reference amino acid sequence, and amino acid substitution (E instead of Q) are reported. MeF had 70% of mutant alleles in both PMN and T cells; MPC12_294 had 70% of mutant alleles in PMN and 75% in T cells.