Choline Polymorphisms in FASD

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ABSTRACT This exploratory/developmental UH2 pilot application to CIFASD addresses the need for improved intervention in Fetal Alcohol Spectrum Disorder (FASD), a leading cause of life-long behavioral and cognitive disability. This proposal focuses on the nutrient choline, a one-carbon donor that is essential for healthy brain development. Polymorphisms in choline-metabolizing genes affect its synthesis, transport, and utilization, and thus affect choline need and efficacy of its use. Strong preclinical data show that choline supplementation – both in utero and postnatally – mitigates the cognitive deficits due to prenatal alcohol exposure (PAE). Clinical studies have more nuanced outcomes, and choline supplements confer more modest or even no benefit; however, variables including age, developmental brain stage, and duration confound the interpretation. Our recent SNP analysis of subjects in the Wozniak intervention found that polymorphisms in the choline transporter SLC44A1 (CTL1) predict who benefited most from choline; specifically, subjects having minor alleles in SLC44A1 have the greatest memory improvement when given supplemental choline. SLC44A1 is ubiquitous and its activity is reduced by low choline intake, and these minor alleles further reduce its activity. Thus, those with the minor alleles are the most vulnerable to choline inadequacy and benefit most from its supplementation. Here, we collaborate with CIFASD investigators to investigate the role of SLC44A1 in FASD. Specifically, we hypothesize that polymorphisms in SLC44A1 significantly influence behavioral outcomes in FASD, in both the presence and absence of choline intervention. Aim 1 tests the hypothesis that, within the Ukrainian intervention trial, those PAE pregnancies with minor alleles in SLC44A1 derive the greatest cognitive benefit from choline supplementation. Aim 2 tests the hypothesis that, of individuals diagnosed with FASD and not receiving choline, those having minor alleles in SLC44A1 will have the poorest cognitive performance. Aim 3 expresses these minor allelic proteins in a human neuronal lineage, to understand the functional consequence of these variants to choline transport and metabolism. Aims 1-2 utilize the CIFASD database, in a collaboration with CIFASD investigators Christina Chambers, Tatiana Foroud and Jeffrey Wozniak, and with choline expert Steven Zeisel. These findings (i) identify who benefits most from choline intervention; (ii) informs how choline improves outcomes in FASD; and (iii) enables optimization of the choline intervention. This study represents the first application of Personalized Medicine to FASD. The results position us to join a CIFASD U01 that would validate SLC44A1's influence in an independent cohort of gestational substance abuse, with testing for additional choline-related polymorphisms that further influence response to choline intervention.