Inborn errors of metabolismGene: HAAO
Comment on list classification: Confirmed with the clinical team that this gene has enough evidence to be green.
Created: 5 Sep 2017, 8:56 a.m.
Comment on list classification: Two unrelated cases are reported in a new publication PMID: 28792876. One case in a consanguineous Lenanese family (Family B) was found to be homozygous for a stop codon, both unaffected parents and 3 unaffected siblings were heterozygous. The second case in a consanguineous family from Iraq (Family A), was homozygous for a c.483dupT variants resulting in a stop codon. Both unaffected parents and 4 unaffected siblings were heterozygous. Metabolites upstream of HAAO in the kynurenine pathway were higher in patients A and B than unaffected family members. Downstream, levels of NAD+ in plasma from the patients were a third to a quarter the levels of unaffected family members. In vitro assays demonstrated that the stop codon variants result in reduced enzyme activity. Knockout mouse model embryos on a niacin-free diet developed similar defects to the patients. Added the 'treatable' tag to indicate that naicin supplementation during gestation prevented the malformations in the null mice.
Created: 11 Aug 2017, 8:59 a.m.
Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal
Multiple congenital malformations; VACTERL-like phenotype
Ellen McDonagh: Comment on mode of pathogenici
gene: HAAO was added gene: HAAO was added to Inborn errors of metabolism. Sources: Expert Review Green Mode of inheritance for gene: HAAO was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: HAAO were set to 27604308; 17334708; 28792876 Phenotypes for gene: HAAO were set to Multiple congenital malformations; VACTERL-like phenotype