Leber congenital amaurosis (LCA) is a term applied collectively to a group of rare inherited retinal degenerative diseases and is characterized by severe loss of vision at birth.  More simply stated, scientist have identified multiple genes mutations that affect the retina or the part of the eye that detects light and color.  Children affected are often legally blind at birth and may have other symptoms that may include involuntary movements, crossed eyes, clouding of the lenses, unusual sensitivity to light and/or cone shape to the front of the eye.  The LCA group contains almost 30 known gene mutations which account for a majority cases of LCA.  In some cases, the gene mutation responsible for LCA diagnosis is unknown.  The prevalence of LCA is considered rare as the disease only occurs in one or two births per 100,000 births.

One of the gene mutations is designated as CRX or LCA-CRX.  The CRX gene provides the instructions to make the cone-rod homeobox protein.  Essentially, this protein is located in the retina and helps photoreceptors mature into cells that are capable of detecting color and light.   

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