H Syndrome: Report of The First Case in African Ethnicity.

H syndrome is an autosomal recessive multisystemic disease with a very low prevalence rate, characterized by indurated cutaneous hyperpigmentation, hypertrichosis, and various systemic manifestations. The syndrome is caused by mutations in SLC29A3 gene on chromosome 10q23, encoding for human equilibrative transporter 3 (hENT3). So far, only 100-120 patients with H syndrome have been described in the literature, with predominance among Indian, North-American, and Arab ethnicities. This case report describes the first one of H-syndrome rarities in African ethnicity, a 30-year-old Sudanese male misdiagnosed with rheumatoid arthritis. The patient exhibited more than 90% of the clinical characteristics of H syndrome including obesity, short stature, characteristic hyperpigmented, sclerotic cutaneous plaques with induration and hypertrichosis, inflammatory arthropathy, hallux valgus, flexion deformity of toes, exophthalmos, cardiac anomaly, hypogonadism, and splenomegaly and characteristic histologic findings of dermal fibrosis, histiocytosis, lymphoid aggregation, and vascular proliferation. H syndrome is an extremely rare autoinflammatory condition that has a complex constellation of pleiotropic manifestations with multisystemic involvement. And while further identification and better pathophysiological understanding of H syndrome are needed, physicians worldwide should be vigilant about the overlapping features of H syndrome with many other rheumatological, cutaneous, and genetic diseases.