Histiocytosis-lymphadenopathy plus syndrome
OMIM number: 602782
Comments closing date: 17/12/2025
Histiocytosis-lymphadenopathy plus syndrome is a spectrum of conditions which is caused by
pathogenic variants in the same gene, SLC29A3. When this gene is working, it makes a protein
which moves molecules inside cells. If a person is born with a mutation in both copies of the gene, they develop symptoms from a group of conditions called histiocytosis-lymphadenopathy plus syndrome. The spectrum was previously described as distinct conditions called H syndrome, pigmented hypertrichosis with insulin dependent diabetes mellitus (PHID),Faisalabad histiocytosis, and familial Rosai-Dorfman disease(RDD). Features of this condition can vary even in the same family, so it is not possible to predict which symptoms a person might develop. Most
people with any form of this condition have an increased number of white blood cells called
histiocytes, which can accumulate in tissues leading to inflammation and organ damage. Features of H syndrome include dark-coloured, hairy lesions on the body, congenital heart defects, hearing loss, short stature, liver problems, and disorders of sexual development. PHID is also associated with these lesions, and also type 1 diabetes mellitus. Faisalabad histiocytosis is linked to joint contractures of the fingers and toes and hearing loss, as well as swelling of the lymph nodes and eyelids. RDD is linked to swelling of the lymph nodes of the neck and other parts of the body. There is no cure for this condition, but each symptom can be treated on its merits.
