One of the primary functions of a species is to procreate and continue its species. This is accomplished by the genetic material which is carried forward from one generation to another. However, an abnormality in an individual's DNA can cause a genetic disorder. From a small mutation in a single gene to the addition or subtraction of an entire chromosome or set of chromosomes can occur, leading to genetic disorders.

Based on the part of the genome that is affected, genetic disorders can be classified as: Single-gene: caused by changes or mutations that occur in the DNA sequence of one gene, multi-factorial: caused by a combination of environmental factors and mutations in multiple genes, chromosomal: caused by abnormalities in chromosome structure as missing or extra copies or gross breaks and rejoinings, mitochondrial: caused by mutations in the nonchromosomal DNA of mitochondria.

Hemophilia, Down’s syndrome, Color blindness, and Huntington’s disease are some of the genetic disorders common in humans.

Down’s syndrome is caused by the occurrence of a 21st chromosome. This disease can affect cognitive ability and affects physical appearance. Mental retardation is also a possibility that cannot be ruled out. Treatment consists of educating the affected person’s family, and encouraging the affected person to take up vocational training.

Hemophilia is a disease characterized by the inability of blood to clot. When an injury occurs and blood flows, blood has the ability to clot and stop further loss. However, in hemophilic people, blood loses the ability to clot leading to loss of blood. It affects males only and females are at best carriers.

Color blindness is characterized by a partial or total inability to distinguish colors. It is genetically transmitted and is incurable. The Ishihara charts aid in determining a person’s level of color blindness. There are two major types of color blindness including red-green color blindness in which people have trouble distinguishing between red and green colors and blue-yellow color blindness.

Genetic disorders generally are incurable and the treatment revolves around diagnosis of the disease and counseling patients and their families.