Additionally, patients with the BRAF exon 15 mutation and MAP2K1 exon 2 mutation had higher rates of LCH onset before age 3 compared with patients carrying the BRAF exon 12 mutation and MAP2K1 exon 3 mutation (p = 0.037; p = 0.0015). Here, BRAF is linked to Langerhans cell histiocytosis.