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GENATLAS PHENOTYPE
last update : 15-11-2023
Symbol ACIP
Location 11q23.3
Name porphyria, acute, intermittent
Other name(s)
  • porphyria, Swedish type
  • porphobilinogen deaminase deficiency
  • uroporphyrinogen synthase deficiency
  • include porphyria Chester type ( MIM176010 )
  • porphyria, acute intermittent, nonerythroid variant
    • Corresponding gene HMBS
    Other symbol(s) AIP
    Main clinical features
  • including an erythroid form and a non-erythroid variant, manifesting mainly in female patients, typically after puberty
  • characterized by acute attacks of neurological dysfunction which may affect the peripheral, autonomic or central nervous system, and potentially life-threatening acute attacks, are precipitated by genetic and environmental factors that induce aminolevulinate synthase 1, the first and rate-limiting enzyme in heme synthesis
  • biochemical diagnosis is based on demonstrating highly elevated plasma or urine levels of ALA and PBG, after excluding other acute porphyrias by analysis of porphyrin markers in urine and feces
    • Genetic determination autosomal dominant
    Function/system disorder metabolism/porphyrin and heme
    Type disease
    Gene product
    Name porphobilinogen deaminase (HMBS)
    Remark(s)
  • mutations in exon 1 (coding and splicing site promoter and exon 3 in the erythroid form
  • p.R26H variant results in an inactive enzyme, which is unable to produce the HMB product (PMID: 36115019))
  • bi-allelic HMBS variants have been reported before as cause of severe encephalopathy with early childhood fatality in acute intermittent porphyria (PMID: 27558376))