Impact of AOC1 and HNMT Variants on the Therapeutic Outcomes of a Histamine Reducing Diet in Autism Spectrum Disorder.

Researchers studied whether a special diet that reduces histamine helps children with autism. They tested 400 Bulgarian children and found that those with high histamine levels who followed the diet showed significant improvements in physical skills, behavior, social-emotional development, thinking skills, and communication. However, children with certain genetic variations didn't improve as much as others, suggesting genetics may affect how well the diet works.

This study examined the effects of a histamine-reducing diet on developmental outcomes in 400 Bulgarian children with autism spectrum disorder, with detailed analysis of 91 children who had elevated histamine levels. Researchers investigated how genetic variants in AOC1 and HNMT genes influenced treatment response. Following the dietary intervention, significant improvements were observed across all five developmental domains measured by the DP-3 test: physical, adaptive behavior, social-emotional, cognitive, and communication skills. All improvements were statistically significant (p < 0.001).

However, children carrying minor alleles of the studied genetic variants showed smaller improvements compared to those with wild-type genes, suggesting genetic factors may influence dietary intervention effectiveness.

Results suggest histamine-reducing diets may benefit autistic children with elevated histamine levels. Genetic testing for AOC1 and HNMT variants could help predict treatment response and personalize dietary interventions. However, replication in diverse populations is needed before widespread clinical implementation.

Sample limited to Bulgarian population, potentially affecting generalizability. Control group comparison used database rather than matched controls. Study type not specified in methodology. Long-term follow-up data not provided. Unclear whether assessors were blinded to genetic status or dietary compliance.

This study aimed to investigate the effects of a histamine-reducing diet on five developmental domains in autism spectrum disorder subjects and the impact of variants in the AOC1 and HNMT genes on the therapeutic outcomes. Four genetic variants (rs2052129, rs10156191, rs1049742, and rs11558538) in AOC1 and HNMT were genotyped in 400 Bulgarian children with ASD. Genotype and allele frequencies were compared to control data from the GnomAD database. Further analysis was conducted on 91 ASD subjects with elevated histamine who followed the histamine-reducing diet.

Significant improvements were observed across all developmental domains measured by the DP-3 test, including physical, adaptive behavior, social-emotional, cognitive, and communication skills. Paired samples T-tests indicated statistically significant increases in all categories (p < 0.001), with physical scores increasing from 82.29 to 89.18, adaptive behavior from 72.68 to 81.35, social-emotional from 71.43 to 80.22, cognitive from 69.33 to 78.66, and communication from 67.36 to 77.54. Minor allele carriers exhibited lower mean improvements across each of the five developmental parameters compared to wild-type carriers, with mean reductions of 0.90 for rs2052129, 0.70 for rs10156191, 2.07 for rs1049742, and 1.94 for rs11558538. These findings highlight the potential role of histamine regulation in autism spectrum disorder, the impact of variants in the AOC1 and HNMT genes on the therapeutic outcome and suggest dietary management as a viable intervention to improve developmental outcomes.