Exploration of Homocysteine Metabolism and Genetics in Autism Spectrum Disorder.

Researchers in Lebanon studied blood chemistry and genetics in 86 people with autism compared to 86 people without autism. They found that people with autism had higher levels of a substance called homocysteine and lower levels of vitamin B9 (folate) in their blood. These differences might be important for understanding autism, but the study was small and the findings need to be confirmed in larger groups of people.

This Lebanese case-control study investigated genetic variants and homocysteine metabolism in 86 individuals with ASD compared to 86 matched controls. The study examined two genetic variants (rs1801133 and rs1801131) and found no significant association with ASD risk, though sample size limitations prevent ruling out small genetic effects. Metabolic analyses revealed significantly elevated homocysteine concentrations and lower vitamin B9 levels in the ASD group, while vitamin B12, glucose, and lipid profiles were similar between groups. Among ASD participants, the TT genotype of rs1801133 was associated with higher homocysteine levels.

The authors acknowledge the preliminary nature of findings and recommend replication in larger cohorts.

Results suggest potential value in monitoring homocysteine and vitamin B9 levels in individuals with ASD. Elevated homocysteine may indicate need for nutritional intervention or supplementation. Genetic testing for studied variants currently has limited clinical utility.

Small sample size insufficient to detect small genetic effects. Single-population study from Lebanon limits generalizability. Preliminary findings require replication in larger, adequately powered cohorts. Unknown confounding factors not addressed.

Understanding the genetic and metabolic profiles of individuals diagnosed with Autism Spectrum Disorder (ASD) is important for clarifying the biological characteristics of this complex disorder. Given the limited data available for the Lebanese population, this case-control study aimed to investigate the association between commonvariants and ASD risk and to examine differences in homocysteine metabolism between Lebanese individuals with ASD and neurotypical controls. From June 2022 to June 2023, 86 individuals with ASD and 86 controls matched for age and sex were recruited. Genotyping of the rs1801133 and rs1801131 variants and biochemical measurements were performed, followed by comparative statistical analyses.

Our results showed no significant association between the rs1801133 or rs1801131 variants and ASD risk (> 0.05). However, the sample size was not sufficient to rule out small genetic effects. Metabolic analyses revealed significantly higher homocysteine concentrations and lower vitamin B9 levels in the ASD group (< 0.0001), while vitamin B12, fasting glucose, and lipid profiles did not differ significantly between groups (> 0.05). Among individuals with ASD, the TT genotype of rs1801133 was associated with elevated homocysteine concentrations (OR = 9.10,= 0.014), whereas neithervariant was associated with vitamin B12 or B9 levels in ASD or control participants.

Future research directions could focus on exploring the role of key enzymes associated with hyperhomocysteinemia in individuals with ASD and on replicating these preliminary findings in larger, adequately powered cohorts.