Langerhans cell histiocytosis, a new clinical phenotype of x-linked lymphoproliferative disease?

Langerhans’ cell histiocytosis (LCH) is a rare disease of unkown cause and is characterized by clonal proliferation of Langerhans cells. Here, we describe the case of a 22-month-old boy with LCH associated with X-linked lymphoproliferative disease (XLP). Sequence analysis of SH2D1A for mutations that cause T-cell dysfunction revealed a CT substitution at nucleotide 462. This is the first case that hints at an association between XLP and LCH.