Normally, hemoglobin is made up of four globin chains, each bound to a heme group.

正常情况下，蛋白由4条珠蛋白链组成，每条珠蛋白链都与一个基团结合。

These four globin chains combine in different ways to give rise to different kinds of hemoglobin.

这四种珠蛋白链以不同的方式结合，形成不同类型的蛋白。

A hemoglobin tetramer with two alpha-globin and two mutated beta-globin proteins is called sickle hemoglobin, or HbS.

由两条α-珠蛋白与两条变异β-珠蛋白构成的蛋白四聚体，称作镰状蛋白，或HbS。

Now hemoglobin is made up of hemes and globins.

蛋白由与珠蛋白构成。

Specifically, the beta-globin chains end up misshapen, and this is because of a mutation in the beta-globin gene or HBB gene.

确切来说，（该病中）β-珠蛋白链发生变形，而这是由β-珠蛋白基因（HBB基因）的突变造成的。

Remember that the globin in your hemoglobin is a protein — and when proteins bind to stuff, they tend to change shape.

蛋白中的珠蛋白是一种蛋白质，当蛋白质和其他物质结合时它们就会改变形状。

Fetal hemoglobin is made up of two alpha- and two gamma-globin chains, so it doesn't include the mutated beta-globins.

HbF由两条α-和两条γ-珠蛋白链构成，不包括突变的β-珠蛋白。

Sickle cell is an autosomal recessive disease, so a mutation in both copies of the beta-globin gene is needed to get the disease.

镰贫是一种常染色体隐性遗传病，因此需要两个β-珠蛋白基因序列均突变才能获得该病。

This oxygen is bound to hemoglobin, which consists of an iron-containing pigment called heme and a protein part called globin.

这些氧气与蛋白结合，蛋白由叫做的含铁的色和叫做珠蛋白的蛋白质部分组成。

Hemoglobin A (or HbA) - made up of two alpha-globin and two beta-globin peptide chains - is the primary hemoglobin affected in sickle cell.

蛋白A（HbA）由两条α-及两条β-珠蛋白肽链构成，是镰贫中主要被影响的蛋白。

All right, as a quick recap: alpha thalassemia is an autosomal recessive disorder caused by deletion of alpha globin genes on chromosome 16.

得！快速回顾一下：α地中海贫是一种常染色体隐性遗传病，由16号染色体上的α珠蛋白基因缺陷引起。

Another preventative medicine is hydroxyurea - which works by increasing the amount of gamma-globin - which results in more fetal hemoglobin, or HbF.

另一种预防药物是羟基脲；它通过增加γ-珠蛋白，以产生更多的胎儿蛋白（HbF）。

Almost always, the sickle cell mutation is a non-conservative missense mutation that results in the sixth amino acid of beta-globin being valine instead of glutamic acid.

镰状细胞突变几乎总是由于非保守区错义突变，导致β-珠蛋白的第6个氨基酸为缬氨酸，而非谷氨酸。

Free hemoglobin in the plasma is bound by a molecule called haptoglobin and gets recycled, which is why a low haptoglobin level is a sign of intravascular hemolysis.

浆游离蛋白与结合珠蛋白结合，并被循环利用，这也是为何低结合珠蛋白水平是管内溶的标志之一。

As a quick recap: sickle cell disease is an autosomal recessive genetic disease where the beta-globin subunit of hemoglobin is misshapen, which causes red blood cells to sickle when deoxygenated.

好！简要回顾一下：镰状细胞病，是常染色体隐性遗传病，其中蛋白的β-珠蛋白发生突变，脱氧情况下会导致细胞镰变。