Purpose
In a large cohort of molecularly characterized inherited retinal disease (IRD) families, we investigated proportions with disease attributable to causative variants in each gene.
Design
Retrospective study of electronic patient records.
Participants
Patients and relatives managed in the Genetics Service of Moorfields Eye Hospital in whom a molecular diagnosis had been identified.
Methods
Genetic screening used a combination of single-gene testing, gene panel testing, whole exome sequencing, and more recently, whole genome sequencing. For this study, genes listed in the Retinal Information Network online resource (
https://sph.uth.edu/retnet/
) were included. Transcript length was extracted for each gene (Ensembl, release 94).
Main Outcome Measures
We calculated proportions of families with IRD attributable to variants in each gene in the entire cohort, a cohort younger than 18 years, and a current cohort (at least 1 patient encounter between January 1, 2017, and August 2, 2019). Additionally, we explored correlation between numbers of families and gene transcript length.
Results
We identified 3195 families with a molecular diagnosis (variants in 135 genes), including 4236 affected individuals. The pediatric cohort comprised 452 individuals from 411 families (66 genes). The current cohort comprised 2614 families (131 genes; 3130 affected individuals). The 20 most frequently implicated genes overall (with prevalence rates per families) were as follows:
ABCA4
(20.8%),
USH2A
(9.1%),
RPGR
(5.1%),
PRPH2
(4.6%),
BEST1
(3.9%),
RS1
(3.5%),
RP1
(3.3%),
RHO
(3.3%),
CHM
(2.7%),
CRB1
(2.1%),
PRPF31
(1.8%),
MY07A
(1.7%),
OPA1
(1.6%),
CNGB3
(1.4%),
RPE65
(1.2%),
EYS
(1.2%),
GUCY2D
(1.2%),
PROM1
(1.2%),
CNGA3
(1.1%), and
RDH12
(1.1%). These accounted for 71.8% of all molecularly diagnosed families. Spearman coefficients for correlation between numbers of families and transcript length were 0.20 (
P
= 0.025) overall and 0.27 (
P
= 0.017), –0.17 (
P
= 0.46), and 0.71 (
P
= 0.047) for genes in which variants exclusively cause recessive, dominant, or X-linked disease, respectively.
Conclusions
Our findings help to quantify the burden of IRD attributable to each gene. More than ...