ADA and H syndrome: Alteration of TRPML1 activity is a potential therapeutic strategy in diseases connected to adenosine dyshomeostasis, with which elevated levels of intracellular adenosine can be found, such as ADA (lymphopenia, SCID) or ENT3 deficits (familial Rosai-Dorfman disease, H syndrome and Faisalabad histiocytosis).