How does a genetic disorder occur?
March 21, 2008 12:38am CST
The genes located in our cromosomes are respoonsible for the genetic disorders. Chromosomes are nuclear structures that become visible as cells divide. They represent the condensation of the cell's nuclear DNA together with histones and other proteins. They can be seen readily through special preparation and staining techniques. Disorders of single genes have been observed clinically because of a phenotypic change related to alterations in a protein or protein pathway that the gene normally would influence. Today, it is possible to define the exact change in the DNA (genotype) that leads to the change in phenotype. These changes are too small to see through a microscope and require a specialized molecular technique to define. By contrast, disorders of chromosomes almost always involve multiple genes and are a reflection of the absence or excess created by numerical or positional abnormalities of chromosome material.