Kidney melanosis associated with a novel HSP-1 Hermansky-Pudlak oculocutaneous albinism mutation: a case report
Abstract Introduction Melanin deposition in the kidney is rare and appears limited to the conditions of oculocutaneous albinism and malignant melanoma with melanuria. Melanin is generally an insoluble polymer, and it is curious how people with albinism who have little or no skin pigmentation can sec...
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2025-07-01
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| Series: | BMC Nephrology |
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| Online Access: | https://doi.org/10.1186/s12882-025-04319-5 |
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| author | Alaa A. Ali Zana Sidiq M. Saleem Shakir S. Jabali Nashwan M. R. Ibrahim Michael D. Hughson |
| author_facet | Alaa A. Ali Zana Sidiq M. Saleem Shakir S. Jabali Nashwan M. R. Ibrahim Michael D. Hughson |
| author_sort | Alaa A. Ali |
| collection | DOAJ |
| description | Abstract Introduction Melanin deposition in the kidney is rare and appears limited to the conditions of oculocutaneous albinism and malignant melanoma with melanuria. Melanin is generally an insoluble polymer, and it is curious how people with albinism who have little or no skin pigmentation can secrete melanin into the bloodstream, have it pass through the glomerular filtration barrier, and be absorbed by renal tubules. Methods The concentration and solubility of melanin were analyzed in kidney tissue and urine of a renal transplant donor who had a pre-nephrectomy biopsy performed on a black kidney. Genetic testing of a donor blood sample found a novel homozygous Hermansky-Pudlak syndrome (HPS) HPS1 mutation (c.70G > T; p.Glu24Ter). Melanin was extracted from a 24-hour urine collection, and tissue and urine melanin concentrations were determined by spectrophotometry. Results In the kidney, non-melanosomal melanin was deposited as granules in the proximal tubular epithelium and as large aggregates within macrophages in renal tubular lumens. The kidney melanin concentration was 2 mg/g of tissue. Urine melanin was mainly water-soluble, with an excretion of eumelanin that is within a reported normal range. Conclusions Water-soluble melanin was excreted in the urine of a kidney donor with a novel HSP1 mutation predicted to produce a truncated protein. This resulted in melanin pigmentation of a kidney transplanted into a normally pigmented sibling. Donor and recipient are healthy 3 years after the transplant. Nevertheless, HSP can be associated with kidney, colon, and lung pathology, and the long-term outlook for the recipient kidney and donor’s health is uncertain. |
| format | Article |
| id | doaj-art-1b6f69db972f4582946564f11d37101d |
| institution | Kabale University |
| issn | 1471-2369 |
| language | English |
| publishDate | 2025-07-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Nephrology |
| spelling | doaj-art-1b6f69db972f4582946564f11d37101d2025-08-20T03:46:03ZengBMCBMC Nephrology1471-23692025-07-012611610.1186/s12882-025-04319-5Kidney melanosis associated with a novel HSP-1 Hermansky-Pudlak oculocutaneous albinism mutation: a case reportAlaa A. Ali0Zana Sidiq M. Saleem1Shakir S. Jabali2Nashwan M. R. Ibrahim3Michael D. Hughson4University of Sulaimani College of Medicine, Shorsh Teaching and Hiwa Oncology HospitalsUniversity of Duhok College of MedicineUniversity of Duhok College of MedicineUniversity of Duhok College of MedicineUniversity of Sulaimani College of Medicine, Shorsh Teaching and Hiwa Oncology HospitalsAbstract Introduction Melanin deposition in the kidney is rare and appears limited to the conditions of oculocutaneous albinism and malignant melanoma with melanuria. Melanin is generally an insoluble polymer, and it is curious how people with albinism who have little or no skin pigmentation can secrete melanin into the bloodstream, have it pass through the glomerular filtration barrier, and be absorbed by renal tubules. Methods The concentration and solubility of melanin were analyzed in kidney tissue and urine of a renal transplant donor who had a pre-nephrectomy biopsy performed on a black kidney. Genetic testing of a donor blood sample found a novel homozygous Hermansky-Pudlak syndrome (HPS) HPS1 mutation (c.70G > T; p.Glu24Ter). Melanin was extracted from a 24-hour urine collection, and tissue and urine melanin concentrations were determined by spectrophotometry. Results In the kidney, non-melanosomal melanin was deposited as granules in the proximal tubular epithelium and as large aggregates within macrophages in renal tubular lumens. The kidney melanin concentration was 2 mg/g of tissue. Urine melanin was mainly water-soluble, with an excretion of eumelanin that is within a reported normal range. Conclusions Water-soluble melanin was excreted in the urine of a kidney donor with a novel HSP1 mutation predicted to produce a truncated protein. This resulted in melanin pigmentation of a kidney transplanted into a normally pigmented sibling. Donor and recipient are healthy 3 years after the transplant. Nevertheless, HSP can be associated with kidney, colon, and lung pathology, and the long-term outlook for the recipient kidney and donor’s health is uncertain.https://doi.org/10.1186/s12882-025-04319-5Hermansky-Pudlak syndromeOculocutaneous albinismMelanosisMelanotic kidneysMelanin circulation |
| spellingShingle | Alaa A. Ali Zana Sidiq M. Saleem Shakir S. Jabali Nashwan M. R. Ibrahim Michael D. Hughson Kidney melanosis associated with a novel HSP-1 Hermansky-Pudlak oculocutaneous albinism mutation: a case report BMC Nephrology Hermansky-Pudlak syndrome Oculocutaneous albinism Melanosis Melanotic kidneys Melanin circulation |
| title | Kidney melanosis associated with a novel HSP-1 Hermansky-Pudlak oculocutaneous albinism mutation: a case report |
| title_full | Kidney melanosis associated with a novel HSP-1 Hermansky-Pudlak oculocutaneous albinism mutation: a case report |
| title_fullStr | Kidney melanosis associated with a novel HSP-1 Hermansky-Pudlak oculocutaneous albinism mutation: a case report |
| title_full_unstemmed | Kidney melanosis associated with a novel HSP-1 Hermansky-Pudlak oculocutaneous albinism mutation: a case report |
| title_short | Kidney melanosis associated with a novel HSP-1 Hermansky-Pudlak oculocutaneous albinism mutation: a case report |
| title_sort | kidney melanosis associated with a novel hsp 1 hermansky pudlak oculocutaneous albinism mutation a case report |
| topic | Hermansky-Pudlak syndrome Oculocutaneous albinism Melanosis Melanotic kidneys Melanin circulation |
| url | https://doi.org/10.1186/s12882-025-04319-5 |
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