(A) Pedigree and segregation of the MAPK8 mutation. The patients, in black, are heterozygous for the mutation. E? indicates individuals whose genetic status could not be evaluated. (B) Electropherograms of partial sequences of MAPK8 corresponding to the mutation in a healthy control (C) and four members of the kindred (II.1, P1, P2, and P3). (C) Schematic illustration of the genomic locus and of the protein encoded by the MAPK8 gene extracted from the Ensembl database. It has 13 exons (I-XIII), 12 of which are coding exons (II-XIII), encoding four isoforms (JNK1α1, JNK1α2, JNK1β1, and JNK1β2), with alternative usage of exon VII or VIII and alternative splicing of exon XIII. The red arrow indicates the position of the mutation.