H syndrome

H syndrome, also known as Histiocytosis-lymphadenopathy plus syndrome or PHID,^[1] is a rare genetic condition caused by mutations in the SLC29A3 gene which encode the human equilibrative nucleoside transporter (hENT3) protein.^[2]

H syndrome
Other names	Histiocytosis-lymphadenopathy plus syndrome
This condition is inherited in an autosomal recessive manner

It is also known as Faisalabad histiocytosis, familial Rosai-Dorfman disease, sinus histiocytosis with massive lymphadenopathy and pigmented hypertrichosis with insulin-dependent diabetes mellitus syndrome. ^[3]

Presentation

This syndrome has a number of different clinical features many of which start with the letter 'H' giving rise to the name of the syndrome. These features include^{[citation needed]}

• Hyperpigmentation
• Hypertrichosis
• Hepatosplenomegaly
• Hearing loss
• Heart anomalies
• Hypogonadism
• Low height (short stature)
• Hyperglycemia/diabetes mellitus
• Hallux valgus/flexion contractures

Exophthalmos, malabsorption and renal anomalies have also been reported.^{[citation needed]}

Genetics

The SLC29A3 gene is located on the long arm of chromosome 10 (10q22).^{[citation needed]}The causative gene was identified in 2010.^[4]

Pathogenesis

This is not understood at present.^{[citation needed]}

Diagnosis

Management

There is no curative treatment for this condition at present. Management is directed to the clinical features.^{[citation needed]}

History

This condition was first described in 1998.^[5]

References

1. Virginia P. Sybert (2017). Genetic Skin Disorders. Oxford University Press. pp. 182–. ISBN 978-0-19-027648-5.
2. Moynihan L M, Bundey SE, Heath D, Jones EL, McHale DP, Mueller RF, Markham, AF, Lench NJ (1998) Autozygosity mapping, to chromosome 11q25, of a rare autosomal recessive syndrome causing histiocytosis, joint contractures, and sensorineural deafness. Am J Hum Genet 62: 1123-1128
3. Dilip, Meena; Chauhan, Payal; Hazarika, Neirita; Kumar Kansal, Naveen (Jan–Feb 2018). "H Syndrome: A Case Report and Review of Literature". Indian Journal of Dermatology. 63 (1): 76–78. doi:10.4103/ijd.IJD_264_17. PMC 5838761. PMID 29527032.
4. Morgan NV, Morris MR, Cangul H, Gleeson D, Straatman-Iwanowska A, Davies N, Keenan S, Pasha S, Rahman F, Gentle D, Vreeswijk MPG, Devilee P, and 10 others. Mutations in SLC29A3, encoding an equilibrative nucleoside transporter ENT3, cause a familial histiocytosis syndrome (Faisalabad histiocytosis) and familial Rosai-Dorfman disease. PLoS Genet. 6: e1000833
5. Moynihan L M, Bundey SE, Heath D, Jones EL, McHale DP, Mueller RF, Markham, AF, Lench NJ (1998) Autozygosity mapping, to chromosome 11q25, of a rare autosomal recessive syndrome causing histiocytosis, joint contractures, and sensorineural deafness. Am J Hum Genet 62: 1123-1128

External links