Health encyclopaedia - Alphabetical Topic List健康百科全书-按字母顺序排列的主题清单

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Causes of Tay-Sachs disease原因泰-萨克斯病

The condition is due to the absence of an essential enzyme that breaks down a substance called ganglioside, present mainly in the nervous system.条件是由于没有一个必不可少的酶分解的物质，所谓的神经节苷脂，目前主要集中于中枢神经系统。 It is the accumulation of this material that is so damaging.它是积累的这种材料是这样的损害。

A recessive genetic disorder is one in which both father and mother must carry the gene before the child can develop the disease.一隐性遗传性疾病是一在双方的父亲和母亲，必须进行基因之前，孩子可以发展的疾病。 Chromosomes come in pairs, each member of a pair having an almost identical set of genes.染色体来在对，每个成员国的一对具有几乎相同的一套基因。

Parents carrying the mutated gene can only have it on one of the gene pairs, the other gene being normal.家长携带突变基因只能有它的其中一个基因对，其他基因被正常。 When sperms and eggs are formed, only one of each chromosome pair enters the sperm or egg.当精子和卵子的形成，其中只有一个，每个染色体配对进入精子或卵子。

So it is pure chance whether the sperm and the egg carry the mutated gene or the normal one.所以这是纯粹的机会，是否精子和卵子进行基因突变或正常1 。 For the disease to occur, a sperm carrying the mutation (50:50 chance) must fertilise an egg carrying the mutation (50:50 chance).为疾病的发生，精子进行基因突变（ 50:50机会）必须受精鸡蛋进行突变（ 50:50机会） 。