Why Do Some Children have Foetal Alcohol Syndrome and Some Do Not?

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For many years the questions has been raised as to why not all children are affected by Foetal Alcohol Syndrome even if the mother was drinking alcohol during her pregnancy. The theory that genetics plays a role in whether a child will have FAS first came about through studying twins. In a sample size 16 sets of twins, which were all exposed to alcohol while in the uterus, out of the 5 sets of identical twins, in each set both children were affected by FAS. Out of the 11 sets of fraternal twins, 4 sets had the same out come as the identical twins, while in the other 7 sets only one child per set was affect by FAS. Through this research it can therefore be understood that it was the difference in DNA of the fraternal twins that lead to only…show more content…
Another area of study is that if the mother has both or one of the alleles ADH1B*2 and ADH1B*3 her child is protected from FAS. ADH1B*2 and ADH1B*3 are polymorphisms of ADH1B which comes from the alcohol dehydrogenase (ADH), which is a catalyzing enzyme involved with the oxidation of ethanol. These alleles code for enzymes that cause oxidation of ethanol to occur at a much faster rate than usual. By having a faster oxidation rate alcohol will be metabolized and detoxified sooner. The alcohol consumed goes into your blood stream and is spread through the body, which could have a teratogenic effect on the foetus, until the alcohol has been completely metabolized. Therefore the faster the alcohol can be metabolized the less chance there is of it getting to the placenta and therefore into the foetus’ bloodstream. Due to the fact that the alcohol won’t be able to get to the foetus because it oxidised much quicker, the foetus is protected from the effects of the alcohol which lead to FAS.
The most recent discovery to provide evidence that genetics is a contributing factor to the development of FAS is the discovery of the exact locus that controls the alcohol sensitivity of the L1 protein. L1 is an essential part of the neural development of foetuses. It is located on the outside of cells and is important to the joining of cells as well as axon control and movement of cells. Phosphorylation, controlled by the enzyme ERK2, occurred inside the L1
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