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

正常情况下，红蛋4条珠蛋链组，每条珠蛋链都与一个红素基团结合。

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

这四种珠蛋链以不同方式结合，形不同类型红蛋。

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

两条α-珠蛋与两条变异β-珠蛋红蛋四聚体，称作镰状红蛋，或HbS。

Now hemoglobin is made up of hemes and globins.

红蛋红素与珠蛋。

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-珠蛋链发生变形，而这是β-珠蛋基因（HBB基因）突变造。

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

HbF两条α-和两条γ-珠蛋链，不包括突变β-珠蛋。

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

记住红蛋中珠蛋是一种蛋质，当蛋质和其他物质结合时它们就会改变形状。

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.

这些氧气与红蛋结合，红蛋叫做红素含铁色素和叫做珠蛋蛋质部分组。

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

红蛋A（HbA）两条α-及两条β-珠蛋肽链，是镰贫中主要被影响红蛋。

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，16号染色体上α珠蛋基因缺陷引起。

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，以产生更多胎儿红蛋（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于非保守区错义突变，导致β-珠蛋第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.

浆游离红蛋与结合珠蛋结合，并被循环利用，这也是为何低结合珠蛋水平是管内溶标志之一。

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，其中红蛋β-珠蛋发生突变，脱氧情况下会导致红细胞镰变。