Vision Science and Eye

Genetical Disorders of Eye

Genetic disorders are caused by mutations in our genes, which modify the resulting proteins.  These mutations may occur spontaneously in an individual or are inherited through the parental chromosomes. They may manifest in the heterozygous state (be present on one chromosome, either paternal or maternal) or in the homozygous state (affecting both alleles).  A mutation that is manifest in the heterozygous state leads to a dominant disorder, whereas mutations that manifest in the homozygous state are referred to as autosomal recessive.  X-linked conditions differ from autosomal types in that women are unaffected or only mildly affected carriers and affected persons are usually male. Other disorders may require the additive effect of mutations in several genes in order to become manifest or require an environmental component; they are then referred to as polygenic or multifactorial.  Some 6,000 human genetic diseases are known and about 1/3rd of these are purely ocular or have ocular manifestations.