Diseases and Treatment: V Genetic Disorders

Colorblindness is a sex-linked recessive trait, meaning the gene responsible for it is located on the X chromosome. Females have two X chromosomes, and if one carries the colorblind gene and the other is normal, the woman will be a carrier (will not express the trait, but can pass it on). Males have one X chromosome and one Y chromosome. If the X chromosome carries the colorblind gene, the male will be colorblind.

The colorblind woman has two X chromosomes, both with the colorblind gene. The normal man has one X chromosome with the normal vision gene.

Sons will inherit the mother's X chromosome with the colorblind gene (and the father's Y chromosome), making them colorblind. Daughters will inherit one X chromosome from each parent. They will have one X chromosome with the colorblind gene (from the mother) and one normal X chromosome (from the father), making them carriers.

Thalassemia is passed down through families from one or both parents. The body's inability to produce enough or abnormal hemoglobin leads to a shortage of healthy red blood cells. The reduced oxygen-carrying capacity of the blood results in anemia, a condition where there are not enough healthy red blood cells or not enough hemoglobin. Thalassemia can range in severity, from mild to severe. There are two main types: alpha and beta thalassemia, each with further subtypes.

Thalassemia is passed down through families from one or both parents. The body's inability to produce enough or abnormal hemoglobin leads to a shortage of healthy red blood cells. The reduced oxygen-carrying capacity of the blood results in anemia, a condition where there are not enough healthy red blood cells or not enough hemoglobin. Thalassemia can range in severity, from mild to severe. There are two main types: alpha and beta thalassemia, each with further subtypes.