Background: H syndrome is an autosomal recessive disease with multisystem involvement caused by mutations in SLC29A3 (OMIM #602782). SLC29A3 gene encodes a protein named hENT3, a part of a family of sodium independent transport of nucleoside which is used for salvage synthesis and can be found in the placenta, uterus, spleen, ovary, lymph nodes, bone marrow and kidneys. The clinical hallmark of the disorder is cutaneous hyperpigmentation, induration and hypertrichosis. Systemic manifestations may include also hepatosplenomegaly, hearing loss, heart anomalies, hypogonadism, short stature, diabetes mellitus, flexion contractures of fingers and toes and hallux valgus. Minor renal abnormalities are described in the literature in 6% of the patients, including: hydronephrosis, renal asymmetry, single kidney, renal cortical cysts, enlarged kidneys, thickening of the renal capsule and small kidneys.
Objective and Methods: To describe severe renal involvement in a patient diagnosed genetically with H syndrome.
Results: Three family members with mutations in SLC29A3 (G427S) showed typical signs of H syndrome. Also, two of them presented with new renal involvement: An 8 years old with mild albuminuria and A 2 years old with steroid resistant nephrotic syndrome. He was managed with Cyclosporine with partial response and albumin infusions twice weekly. Renal biopsy revealed glomerular basement membrane thickening with little or no cellular proliferation or infiltration on light microscopy consistent with membranous nephropathy.
Conclusions: Severe glomerular involvement can be a rare manifestation of H syndrome.
