chr1-68446862-T-A

Position:

• chr1-68446862-T-A

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PP4_Moderate PVS1 PP1 PM3 PM2_Supporting

This summary comes from the ClinGen Evidence Repository: The NM_000329.3(RPE65):c.95-2A>T variant disrupts a canonical splice site in intron 2 and is predicted to lead to skipping of a critical exon in which missense variants have previously been established as a mechanism of disease (PVS1). At least 6 probands have been reported with this variant, one of whom displayed markedly impaired night vision (0.5 pts), reduced visual acuity 20/60 from an early age (1 pt), nystagmus (1 pt), RPE demelanization (0.5 pts), poor pupillary light response (0.5 pts), significant outer nuclear layer preservation for the severity of visual loss (1 pt), nondetectable ERG responses from rods (0.5 pts) and cones (1 pt), and minimal autofluorescence (2 pts), which together are highly specific for RPE65 retinopathy (8 pts total, PP4_Moderate, PMID:20604683). The proband's affected sibling II:2 is also homozygous for this variant (PP1). At least 3 probands with the required phenotype of extinguished ERG harbor the variant in the homozygous state (1 point, PMID:20604683, PMID:17724218, PMID:15024725, PM3). This variant is present in gnomAD v.2.1.1 at a GrpMax allele frequency of 0.00002298, with 3 alleles / 34592 total alleles in the Admixed American population, which is lower than the ClinGen LCA / eoRD VCEP PM2_Supporting threshold of <0.0002 (PM2_Supporting). In summary, this variant meets the criteria to be classified as Pathogenic for RPE65-related recessive retinopathy based on the ACMG/AMP criteria applied, as specified by the ClinGen LCA/eoRD VCEP: PVS1, PP4_Moderate, PM2_Supporting, PM3, and PP1. (VCEP specifications version 1.0.0; date of approval 09/21/2023). LINK:https://erepo.genome.network/evrepo/ui/classification/CA226591/MONDO:0100368/120

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000068 (0 hom.)
• Consequence: RPE65 NM_000329.3 splice_acceptor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic reviewed by expert panel P:12 O:1
• Conservation: PhyloP100: 7.67

Genes affected

RPE65 (HGNC:10294): (retinoid isomerohydrolase RPE65) The protein encoded by this gene is a component of the vitamin A visual cycle of the retina which supplies the 11-cis retinal chromophore of the photoreceptors opsin visual pigments. It is a member of the carotenoid cleavage oxygenase superfamily. All members of this superfamily are non-heme iron oxygenases with a seven-bladed propeller fold and oxidatively cleave carotenoid carbon:carbon double bonds. However, the protein encoded by this gene has acquired a divergent function that involves the concerted O-alkyl ester cleavage of its all-trans retinyl ester substrate and all-trans to 11-cis double bond isomerization of the retinyl moiety. As such, it performs the essential enzymatic isomerization step in the synthesis of 11-cis retinal. Mutations in this gene are associated with early-onset severe blinding disorders such as Leber congenital. [provided by RefSeq, Oct 2017]

LOC124904198 (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 14 ACMG points.

• PVS1: For more information check the summary or visit ClinGen Evidence Repository.
• PM2: For more information check the summary or visit ClinGen Evidence Repository.
• PM3: For more information check the summary or visit ClinGen Evidence Repository.
• PP1: For more information check the summary or visit ClinGen Evidence Repository.
• PP4: For more information check the summary or visit ClinGen Evidence Repository.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
RPE65	NM_000329.3	c.95-2A>T		splice_acceptor_variant, intron_variant		ENST00000262340.6	NP_000320.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
RPE65	ENST00000262340.6	c.95-2A>T		splice_acceptor_variant, intron_variant		1	NM_000329.3	ENSP00000262340.5

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152218 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000654

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000199 AC: 5 AN: 251428 Hom.: 0 AF XY: 0.0000221 AC XY: 3 AN XY: 135898

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000867

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000176

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000684 AC: 10 AN: 1460934 Hom.: 0 Cov.: 32 AF XY: 0.00000963 AC XY: 7 AN XY: 726796

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000671

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000360

Gnomad4 OTH exome AF: 0.0000497

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152218 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74364

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.0000654

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.0000227

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000116 AC: 1

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:12 Other:1

Revision: reviewed by expert panel

Submissions by phenotype

Leber congenital amaurosis Pathogenic:3

Pathogenic, no assertion criteria provided	research	Sharon lab, Hadassah-Hebrew University Medical Center	Jun 23, 2019	- -
Pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Sep 16, 2020	- -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Jan 19, 2023	Variant summary: RPE65 c.95-2A>T is located in a canonical splice-site and is predicted to affect mRNA splicing resulting in a significantly altered protein due to either exon skipping, shortening, or inclusion of intronic material. Several computational tools predict a significant impact on normal splicing: four predict the variant abolishes a 3 prime acceptor site; four predict the variant creates a 3 prime acceptor site. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 2e-05 in 251428 control chromosomes. c.95-2A>T has been reported in the literature in multiple individuals affected with Leber Congenital Amaurosis. These data indicate that the variant is very likely to be associated with disease. Six clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

not provided Pathogenic:2 Other:1

not provided, no classification provided	literature only	Retina International	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Sep 01, 2023	RPE65: PVS1, PM2, PM3 -
Pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Jun 13, 2023	- -

Leber congenital amaurosis 2;C3151086:Retinitis pigmentosa 20 Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Dec 17, 2023	This sequence change affects an acceptor splice site in intron 2 of the RPE65 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in RPE65 are known to be pathogenic (PMID: 9326941, 9501220, 9843205, 18632300). This variant is present in population databases (rs61751279, gnomAD 0.009%). Disruption of this splice site has been observed in individuals with RPE65-related conditions (PMID: 15024725, 17724218, 21151602). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 98899). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Jul 25, 2017	- -

Leber congenital amaurosis 2 Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Feb 13, 2024	- -
Pathogenic, no assertion criteria provided	research	Laboratory of Genetics in Ophthalmology, Institut Imagine	-	- -

RPE65-related recessive retinopathy Pathogenic:1

Pathogenic, reviewed by expert panel

curation

ClinGen Leber Congenital Amaurosis/early Onset Retinal Dystrophy Variant Curation Expert Panel, ClinGen

Dec 22, 2023

The NM_000329.3(RPE65):c.95-2A>T variant disrupts a canonical splice site in intron 2 and is predicted to lead to skipping of a critical exon in which missense variants have previously been established as a mechanism of disease (PVS1). At least 6 probands have been reported with this variant, one of whom displayed markedly impaired night vision (0.5 pts), reduced visual acuity 20/60 from an early age (1 pt), nystagmus (1 pt), RPE demelanization (0.5 pts), poor pupillary light response (0.5 pts), significant outer nuclear layer preservation for the severity of visual loss (1 pt), nondetectable ERG responses from rods (0.5 pts) and cones (1 pt), and minimal autofluorescence (2 pts), which together are highly specific for RPE65 retinopathy (8 pts total, PP4_Moderate, PMID: 20604683). The proband's affected sibling II:2 is also homozygous for this variant (PP1). At least 3 probands with the required phenotype of extinguished ERG harbor the variant in the homozygous state (1 point, PMID: 20604683, PMID: 17724218, PMID: 15024725, PM3). This variant is present in gnomAD v.2.1.1 at a GrpMax allele frequency of 0.00002298, with 3 alleles / 34592 total alleles in the Admixed American population, which is lower than the ClinGen LCA / eoRD VCEP PM2_Supporting threshold of <0.0002 (PM2_Supporting). In summary, this variant meets the criteria to be classified as Pathogenic for RPE65-related recessive retinopathy based on the ACMG/AMP criteria applied, as specified by the ClinGen LCA/eoRD VCEP: PVS1, PP4_Moderate, PM2_Supporting, PM3, and PP1. (VCEP specifications version 1.0.0; date of approval 09/21/2023). -

Leber congenital amaurosis 2;C3151086:Retinitis pigmentosa 20;C5231465:Retinitis pigmentosa 87 with choroidal involvement Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Jun 18, 2024

- -

Retinal dystrophy Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Blueprint Genetics

Dec 18, 2018

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.49	D
BayesDel_noAF	Pathogenic	0.37
CADD	Pathogenic	33
DANN	Uncertain	1.0
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	0.98	D
GERP RS		5.9

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		0.98		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.44		Position offset: -6
DS_AL_spliceai		0.98		Position offset: -2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs61751279; hg19: chr1-68912545;