SAG retinitis pigmentosa is a type of retinitis pigmentosa (RP) that's caused by a mutation in the SAG gene. SAG stands for S-antigen gene, which is located on chromosome 2q37. A mutation in the SAG gene can also cause Oguchi disease-1, a type of congenital stationary night blindness.​ RP is a progressive disorder that typically begins in childhood. The rate of progression and degree of visual loss varies from person to person. Many people with RP are legally blind by age 40.

Symptoms include difficulty seeing at night, difficulty adjusting to light changes, difficulty seeing in poor weather, tunnel vision, difficulty seeing colors, especially blue, gradual vision loss, clumsiness due to poor vision, sensation of twinkling or flashing light, sensitivity to bright light (photophobia)​

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This is for informational purposes only. For medical advice or diagnosis, consult a professional.

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