Germline mutations in SLC29A3 (at 10q23), which is associated with H syndrome (histiocytosis-lymphadenopathy plus syndrome), Faisalabad histiocytosis, and pigmented hypertrichotic dermatosis with insulin-dependent diabetes, have been found in cases of familial RDD. This evidence concerns the gene SLC29A3 and sinus histiocytosis with massive lymphadenopathy.