Abnormal Development - Fetal Alcohol Syndrome

Introduction

This disorder was clinically described (USA) in humans about 30 years ago (1973), while historically alcohol's teratogenic effects were identified in the early 20th century in a mix with the prohibition cause of the period.

Consuming alcohol during pregnancy is the cause of Fetal Alcohol Syndrome (FAS), consisting of a variable degree of birth defects and mental retardation, initially identified by a reduced head size and distinctive facial features.

Similar effects without the obvious alterations to appearance, but with nervous system effects, are sometimes typified as Fetal Alcohol Effects (FAE). Alcohol is able to cross the placenta from maternal circulation through the placenta into fetal circulation.

Exposure of embryos in vitro to ethanol simulates premature differentiation of prechondrogenic mesenchyme of the facial primordia. This result may explain some facial abnormalities associated with FAS, the mechanism of which is still unknown (More? Hoffman and Kulyk , 1999).

Alcohol intake is also one of several factor known to impact upon birthweight. In Australia (2005) 6.4% of all liveborn babies were of low birthweight (less than 2,500 grams).

Cell death (apoptosis) induced by alcohol has also been suggested as relevant to craniofacial abnormalities and neurological development. The neurological effects (FAS limits IQ to around 70) may be due to cell death in the embryonic neuroepithelium (the outer layer of the developing neural tube) at an early developmental stage. Some additional evidence suggests that alcohol could also directly damage DNA.

These developmental abnormalities are maternal in origin and are not genetic, though there are probably genetic elements involved with alcoholism (More? OMIM alcoholism).

This Syndrome is 100% preventable.