The Prevalence of Single Nucleotide Polymorphisms of the AOC1 Gene Associated with Diamine Oxidase (DAO) Enzyme Deficiency in Healthy Newborns: A Prospective Population-Based Cohort Study

Abstract

Background/Objectives: The prevalence of the diamine oxidase (DAO) enzyme deficiency of a genetic origin has not been previously assessed. A prospective population-based study was conducted in a sample of 200 healthy newborns aimed to determine the prevalence of DAO enzyme deficiency caused by single nucleotide polymorphism (SNP) variants of the AOC1 gene. Methods: Genotyping was performed in oral mucosa samples collected around 2 days after birth. The four more frequent SNPs, c.47C>T (rs10156191), c.995C>T (rs1049742), c.1990C>G (rs10449793), and c.691G>T (rs2052129), were analyzed. Results: DAO deficiency was present in 132 newborns, with a prevalence of 66% (95% confidence interval [CI] 59–73%). The rs10449793 variant showed a prevalence of 46%, followed by rs10156191 with a prevalence of 42.5%, and rs2052129 with a prevalence of 39.5%. The variant rs1049742 showed the lowest prevalence (9.5%). The frequency of one, two, three, or four SNPs was 23%, 23.5%, 10.5%, and 9%, respectively. In all fours SNP variants, heterozygous carriers were more frequent than homozygous carriers (19% homozygosity). Differences in the prevalence of DAO deficiency between males (68%, 66/96) and females (63.4%, 66/104) were not found (p = 0.885). The prevalence in Caucasian newborns was 66.5% (123/185), as compared with 60% (9/15) in Latin Americans (p = 0.821). Conclusions: This study carried out in healthy newborns indicates that there is a high prevalence (66%) of DAO deficiency of a genetic origin in the general population.