Dr. James is the Director of the Metabolic Genomics Laboratory at ACHRI and a collaborator of the Arkansas Center for Birth Defects Research and Prevention. Her research is focused on the understanding of the metabolic and genetic factors that may be mechanistically involved in the etiology of autism, Down syndrome, and childhood acute lymphoblastic leukemia (ALL). The Metabolic Genomics team measures plasma levels of metabolites that are predictive of impaired methylation capacity and oxidative stress. In addition, the lab measures genetic polymorphisms that could contribute to an increased risk of oxidative stress and decreased glutathione-mediated antioxidant defense.
Most recently, this approach has been used to study metabolic profiles and related genotypes that may increase the risk of autism. Autism is a complex neurodevelopmental disorder characterized by impairment in social interaction and language accompanied by social withdrawal and repetitive hyper-focused behaviors. The abnormal metabolic and genetic profiles discovered in Metabolic Genomics lab indicate that autistic children may be more vulnerable to environmental factors that increase oxidative stress. It is generally accepted that both genetic and environmental factors interact to negatively affect neurologic and immunologic function during prenatal and postnatal development in autistic children. Recent evidence from Dr. James’ laboratory suggests that autism may involve inherited metabolic aberrations that secondarily affect neurologic and immunologic function during prenatal and postnatal development. If proven correct, this model supports the possibility that normalization of the metabolic imbalance with targeted intervention strategies could potentially improve symptoms and arrest the progression into autism.
Dr. James works closely with Charlotte Hobbs, MD, to define maternal metabolic risk factors for having a child with a congenital heart defect or neural tube defect. She also collaborates with researchers at the National Center for Toxicological Research, University of Utah, the University of California-Davis M.I.N.D. Institute, University of British Columbia, McGill University and University of California Davis to investigate metabolic imbalance in Down syndrome, intrauterine growth retardation, autism, cystic fibrosis, colon cancer and alcoholic hepatitis, respectively.
James SJ, Pogribna M, Pogribny IP, Melnyk S, Hine RJ, et al. Abnormal folate metabolism and mutation in the methylenetetrahydrofolate reductase gene may be maternal risk factors for Down Syndrome, Am. J. Clin. Nutr., 70: 495-501, 1999.
James SJ, Melnyk S, Pogribna M, Pogribny IP, and Caudill M. Evaluation of S-adenosylhomocysteine and DNA hypomethylation: potential epigenetic mechanisms for homocysteine-related pathology. Journal of Nutrition, 132: 2361S-2366S , 2002.
James S J . Maternal metabolic phenotype and Down syndrome: Beyond genetics. Invited editorial. Am. J. Med. Genet. 127A, 1-4, 2004.
James SJ. The molecular dynamics of folate metabolism and DNA methylation: implications for disease susceptibility and progression. Chapter 7 in Methylenetetrahydrofolate Reductase Polymorphisms and Disease, edited by Ueland PM and Rozen R. 2004
James SJ, Melnyk SB, Jernigan S, Janak L, Cutler P, Neubrander JM. Metabolic biomarkers of increased oxidative stress and impaired methylation capacity in children with Autism. Amer. J. Clin. Nutr. 80:1611-17, 2004.
*To find additional publications by this author, please visit Pubmed Central, a National Institutes of Health-operated site for electronic distribution of life sciences research reports.
The National Institutes of Health: Metabolic Biomarkers of Autism: Genetic Predisposition and Nutritional Intervention
Environmental Protection Agency: Fallon Project
CDC: Mechanisms of Oxidative Stress in Children
Arkansas Children’s Hospital Foundation
Arkansas Center for Birth Defects Research and
13 Children's Way, Mail Slot 512-40
Little Rock, Arkansas 72202