Retinitis Pigmentosa is rare and group of genetic disorder. It is an inherited disease which is passed on from parents to their offsprings.
It is caused due to mutation in genetic code. Due to alteration in genes there is progressive degeneration of photoreceptor cells present on retina.
There are three ways in which RP can be inherited or passed on:
1. Autosomal Dominant
2. Autosomal Recessive
Autosomal Dominant Retinitis Pigmentosa is due to defect in one copy of gene which is important for functioning of retina and light sensitive cells present on it. Autosomal dominant RP has 50% risk of passing from a parent to their child. It equally effects male and female.
Autosomal Recessive Retinitis Pigmentosa- Defect in both the genes responsible for retina functioning will lead to RP. In this condition child will inherit copy of faulty gene from mother and father, but they do not have symptoms of RP.In Autosomal Recessive RP, one normal copy is enough to keep the retina healthy and proper vision. Autosomal Recessive RP has 25% risk of travelling from one generation to other.
X-Linked RP- In this gene associated with RP is present in X chromosome. In males one copy of faulty gene is enough to cause RP and in women both copies must be faulty.
RP is known to be caused by mutation in more than 60 genes. Mutation in any one of these genes leads to RP. Genes causing RP plays an important role in structure and function of retina and photoreceptor cells which are responsible for sight.
There are four common genes, alteration in which leads to degeneration of rods and cones, leading to blindness in long run.