Neuropathological alterations in patients with FAS have included most frequently microcephaly, cerebellar dysgenesis, cerebral nuclear dysgenesis, agenesis of the corpus callosum, and neuroglial heterotopia s, both macroscopic and microscopic. Microscopic heterotopia s are the most common. Neural tube defects have included lumbosacral myelomeningocele and anencephaly. Few differences have been found between intermittent versus daily alcohol use with respect to morphological abnormalities. One class of molecules known to have effects on both cellular differentiation and proliferation is the retinoids.
Ethanol is a teratogen.
A teratogen is an agent that causes birth defects. There is a possible role of retinoids in the teratogenic effects of ethanol. The defects may be morphological, physiological, biochemical, or behavioral. The behavioral effects are often of a more subtle nature and thus may go undetected. FAS is characterized by such things as growth deficiency, altered morphogenesis, and central nervous system dysfunction.