Sentence Examples


  • Although there are eight steps in heme biosynthesis, there are only seven types of porphyrias; a defect in ALA synthase activity does not have a corresponding porphyria.
  • AIP is caused by a deficiency of porphobilinogen deaminase, which occurs due to mutations in the hydroxymethylbilane synthase gene (HMBS) located at 11q23.3.
  • When heme levels are low, greater quantities of delta-aminolevulinic acid (ALA) synthase are produced.