Heme oxygenase-1 deficiency as an extremely rare cause of AA-type renal amyloidosis: Expanding the clinical features and review of the literature

Clin Rheumatol. 2023 Feb;42(2):597-606. doi: 10.1007/s10067-022-06465-9. Epub 2022 Dec 11.


Heme oxygenase-1 (HMOX-1) is an enzyme that regulates heme degradation. Antiinflammatory, antioxidant, and cytoprotective effects of HMOX-1 were also described. It is encoded by the HMOX1 gene, and biallelic mutations cause HMOX-1 deficiency, which is a rare chronic multisystemic inflammatory disorder. This inflammatory status could lead to the development of secondary AA-type amyloidosis theoretically. Here, we report a 30-year-old male with AA-type renal amyloidosis due to a chronic inflammatory condition of unknown origin. Paternal consanguinity and dysmorphic features raised suspicion of a rare genetic disorder. Clinical exome sequencing (CES) confirmed the HMOX-1 deficiency diagnosis related to homozygous missense G139V mutation. To the best of our knowledge, our patient is the eleventh HMOX-1 deficiency case in the literature. Also, HMOX-1 deficiency-related systemic AA-type amyloidosis has not been reported before.

Keywords: Amyloidosis; HMOX-1; Inflammation; Serum amyloid A.

Publication types

  • Case Reports
  • Review

MeSH terms

  • Adult
  • Amyloidosis* / complications
  • Amyloidosis* / diagnosis
  • Amyloidosis* / genetics
  • Heme Oxygenase-1 / genetics
  • Humans
  • Male
  • Renal Insufficiency* / complications
  • Serum Amyloid A Protein


  • Heme Oxygenase-1
  • Serum Amyloid A Protein

Supplementary concepts

  • Heme Oxygenase 1 Deficiency
  • AA amyloidosis