SNP Shot: Genomic Insights

Ocular albinism is an inherited disorder that mainly impacts the eyes. It leads to a reduction in pigment (coloring) in the iris, the colored part of the eye, and the retina, the light-sensitive tissue at the back of the eye. Proper eye pigmentation is crucial for typical vision.

Hallmarks of ocular albinism include significantly reduced visual sharpness (visual acuity) and difficulties with depth perception due to impaired binocular vision (stereoscopic vision). While the vision impairment is permanent, it doesn't progress. Other associated eye conditions are rapid, uncontrollable eye movements (nystagmus), misaligned eyes (strabismus), and heightened light sensitivity (photophobia). Many individuals with ocular albinism also present with optic nerve abnormalities, which impact the transmission of visual information from the eye to the brain.

Different from certain other albinism types, ocular albinism typically doesn't noticeably affect skin and hair color. Individuals might have a slightly paler complexion than family members, but these differences are generally subtle.

The most prevalent type of ocular albinism is the Nettleship-Falls type, also known as type 1. Other ocular albinism forms are much less common and can present with additional symptoms, such as hearing impairment.

Inheritance:

Ocular albinism type 1 follows an X-linked inheritance pattern. X-linked conditions occur when the mutated gene responsible for the disorder resides on the X chromosome, one of the sex chromosomes. Males, possessing only one X chromosome, require only one altered copy of the GPR143 gene in each cell to exhibit the characteristic signs of ocular albinism. Since females have two X chromosomes, women carrying just one copy of a GPR143 mutation in each cell generally do not experience significant vision loss or other major eye problems. However, they may show minor retinal pigmentation changes detectable during an eye exam.