Prenatal-onset neurodevelopmental disorders secondary to toxins, nutritional deficiencies, and maternal illness.

Neurodevelopmental disorders result from an inordinate number of genetic and environmental causes during the embryological and fetal periods of life. In the clinical setting, deciphering precise etiological diagnoses is often difficult. Newer screening technologies allow a gradual shift from traditional nature-versus-nurture debates toward the focused analysis of gene-by-environment interactions (G X E). Further understanding of developmental adaptation and plasticity requires consideration of epigenetic processes such as maternal nutritional status, environmental toxins, maternal illnesses, as well as genetic determinants, alone or in combination. Appreciation of specific G X E mechanisms of neurodevelopmental pathogenesis should lead to better risk-modifying or preventive strategies. We provide a brief overview of clinical and experimental observations that link prenatal-onset toxic exposures, metabolic disturbances, and maternal illnesses to certain neurodevelopmental disorders.