Loss of function polymorphisms in NAT1 protect against spina bifida

Area of Science:

• Genetics
• Developmental Biology
• Pharmacogenomics

Background:

• Folic acid supplementation is crucial for preventing neural tube defects like spina bifida.
• N-acetyltransferase 1 (NAT1) plays a role in folate breakdown and the processing of environmental compounds.
• Genetic variations in NAT1 may alter susceptibility to spina bifida through folate pathways or toxin metabolism.

Purpose of the Study:

• To investigate the association between NAT1 gene polymorphisms and spina bifida risk.
• To determine if specific NAT1 genotypes influence folate metabolism or the detoxification of potential teratogens.

Main Methods:

• Genotyping of individuals with spina bifida and their parents for six functional NAT1 single nucleotide polymorphisms (SNPs).
• Definition of a composite NAT1 genotype based on the identified SNPs.
• Statistical analysis (log-linear models) to assess the relationship between maternal/offspring genotypes and spina bifida risk.

Main Results:

• Heterozygous parents showed a preference for transmitting the common NAT1 allele to affected offspring.
• Specific maternal and offspring composite NAT1 genotypes were significantly associated with spina bifida risk (P < 0.01).
• NAT1 variants associated with reduced enzyme activity appeared protective against spina bifida.

Conclusions:

• Functional NAT1 polymorphisms are linked to spina bifida risk, impacting both maternal and offspring genotypes.
• Reduced NAT1 enzyme activity may confer protection by altering folate catabolism or reducing the formation of teratogenic metabolites.
• These findings highlight the role of NAT1 in spina bifida etiology and suggest potential targets for prevention strategies.