X-linked retinitis pigmentosa (XLRP) represents about 15% of cases of retinitis pigmentosa.There may be variation in disease severity depending on the precise mutation.
Inheritance: X-linked
|
Gene
|
Chromosome
|
Percent of Cases
|
|
RPGR (retinitis pigmentosa GTPase regulator
|
Xp11.4
|
80%
|
|
RP2 (RP2 activator of ARL GTPase)
|
Xp11.3
|
5-15%
|
Clinical features in males:
(1) night blindness
(2) early-onset myopia
(3) progressive loss of peripheral vision, with dysfunction of rods and cones
(4) rapid progression, with blindness in 20's or 30's
(5) attenuated retinal blood vessels
(6) visual field loss
(7) diminished or absent electroretinogram responses
(8) macular abnormalities
(9) bone-spicule-like pigment deposits
Female carriers may show a range of disease from asymptomatic to severe disease.
Factors associated with slow disease progresion:
(1) mutations in RPGR exons 1 to 14
(2) sine pigmento RP
(3) absence of high myopia
