Autosomal recessive
H syndrome is caused by changes in both copies of SLC29A3, which transports nucleosides inside cells, including in the lysosomes of immune cells. It is part of a spectrum of SLC29A3 disorders marked by excess build-up of histiocytes, a type of immune cell.
Signs and symptoms
Patches of darkened skin with excess hair, typically on the lower body, are a characteristic feature. Other features include hearing loss, short stature, an enlarged liver, heart abnormalities and reduced hormone production by the testes. Less often there are swollen lymph nodes, joint contractures, eye changes or raised inflammatory markers.
What a diagnosis changes
Care includes hearing support, monitoring for diabetes, heart, growth and hormone problems, and dermatology follow-up. Genetic counselling is recommended; parents are usually carriers, each future child may be affected, and carrier testing can be offered to relatives.
Genes analysed
Also known as
Asrar Facharzt Haque syndrome; HJCD; SLC29A3 spectrum disorder
