Proportions of cases caused by various RP genes based on data from our group (May, 2002)
 
Gene  # unrelated patients surveyed # with mutation Percentage of all RP*
RHO (rhodopsin) (1-4) 363 with ADRP and

126 with ARRP

90 (25%)

1 (1%) 

10.0%

0.4

RDS (RDS/peripherin) (5) 135 with ADRP and

92 with ARRP

8 (3.5%) (combines ADRP + ARRP + digenic RP) 3.2
ROM1 (5) (digenic RP with RDS) 173 with ADRP and 

142 with ARRP

4 (1.3%) (combines ADRP + ARRP + digenic RP) 0 (overlap with RDS)
NRL (neural retina leucine zipper transcription factor) (6) 189 with ADRP 4 (2.0%) 0.8
RP1 (7) 241 with ADRP 17 (5.6%)** 2.2
PDE6A (alpha subunit of rod cGMP-phosphodiesterase) (8) 164 with ARRP 6 (3-4%) 1.8
PDE6B (beta subunit of rod cGMP-phosphodiesterase) (9) 92 with ARRP 4 (4%) 2.2
CNGA1 (alpha subunit of the rod cGMP-gated cation channel) (17) 173 with ARRP

94 with ADRP

3 (1.7%)

0 (0%)

0.9
RPE65 (10) 162 with ARRP

45 with LCA

3 (1.9%)

7 (16%)***

0.9
RGR (11) 182 with ARRP 1 (0.5%) 0.3
RPGRIP (12) 57 with LCA  3 (5%)***  
MYO7A (13) 66 with Ush1 19 (29%) 2.9
CRX (14) 36 with ARRP

55 with LCA

1 (3%)

2 (4%)***

1.0
NR2E3 (19) (submitted for publication) 19 with clumped pigment RP 8 (42%) 0.2 
RPGR (15) and unpublished results 140 with XLRP 93 (66%) 6.6
RP2 (15) and unpublished results 140 with XLRP 9 (6.6%) 0.6

Total percent of RP cases with mutations in genes already screened:  34%

Notes to table:
Many recently identified RP genes have not yet been screened.
*To calculate the percentage of all RP caused by each gene, we assumed the following breakdown of RP cases:
ADRP (autosomal dominant RP) = 40%
ARRP (autosomal recessive RP) = 35%
Syndromic ARRP: Usher = 10%, Bardet-Biedl = 5%
XLRP (X-linked RP) = 10%.
** Some of the percentages have been corrected for the fact that patients with known mutations were excluded from the analysis of some genes.
***Patients with LCA (Leber congenital amaurosis) are not included in the calculation of percentages of RP cases with known primary gene defects, since most studies of the prevalence of RP do not count this disease as a form of RP.
****Patients with clumped pigmentary retinal degeneration are estimated to account for 0.5% of RP cases.16

REFERENCE LIST

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 9.  McLaughlin,M.E., Ehrhart,T.L., Berson,E.L., and Dryja,T.P. (1995) Mutation spectrum of the gene encoding the ? subunit of rod phosphodiesterase among patients with autosomal recessive retinitis pigmentosa. Proc.Natl.Acad.Sci.USA, 92,3249-3253.
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