Genetic disorder

A genetic disorder, or genetic disease is a disease caused by abnormal expression of one or more genes in a person causing a clinical phenotype. There are a number of possible causes for genetic defects:

Single gene disorders

A number of genetic disorders are due to the change of a single gene, resulting in an enzyme or other protein not being produced or having altered functionality, they are called monogenic disorders. The change can be trivial and relatively harmless in its effects, such as color blindness, or lethal such as Tay-Sachs. Other disorders, though harmful to those afflicted with them, appear to offer some advantage to carriers; as in carriers of sickle cell anemia and thalassemia appearing to have enhanced resistance to malaria. Several hereditary diseases are sex-linked, meaning that they afflict one sex much more common than the other because the mutation is located on the X (or, rarely, on the Y) chromosome.

Related Topics:
Gene - Enzyme - Protein - Monogenic - Color blindness - Tay-Sachs - Sickle cell anemia - Thalassemia - Malaria - Sex-linked

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Transmission of single gene disorders

Where genetic disorders are the result of a single mutated gene they can be passed on to subsequent generations in the following ways, however genomic imprinting and uniparental disomy may affect inheritance paterns.

Related Topics:
Genomic imprinting - Uniparental disomy

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