chr1-68439059-T-G

Position:

• chr1-68439059-T-G

Variant summary

Our verdict is Likely benign. Variant got -6 ACMG points: 2P and 8B. BA1 PP3_Moderate

This summary comes from the ClinGen Evidence Repository: NM_000329.3(RPE65):c.881A>C is a missense variant that causes substitution of lysine with threonine at position 294. This variant is present in gnomAD v.2.1.1 at a GrpMax allele frequency of 0.03554, with 1312 alleles / 35390 total alleles in the Admixed American population (with 33 homozygotes), which is higher than the ClinGen LCA / eoRD VCEP BA1 threshold of >0.008 (BA1). This variant has been reported in at least 1 proband with early-onset severe retinal dystrophy who harbored the variant in the heterozygous state (PMID:19431183) with the NM_000329.3(RPE65):c.1078G>C (p.Ala360Pro) variant in trans and a 22-bp deletion within exon 12 in cis (PMID:19431183). However, the proband was not counted for the PM3 or BP2 codes because the other two variants have not yet been classified by the ClinGen LCA / eoRD VCEP. The meta-predictor REVEL gives a score of 0.974, which is above the ClinGen LCA/eoRP VCEP PP3 threshold of >0.773 and predicts a damaging effect on RPE65 function (PP3_Moderate). The variant exhibited 16%-68% enzymatic activity in a retinoid isomerase assay relative to the wild-type control, which is between the ClinGen LCA / eoRD VCEP thresholds of <10% activity (PS3_Supporting) and >50% activity (BS3_Supporting), so neither functional study code is met (PMID:16150724, PMID:19431183). Another missense variant in the same codon, NM_000329.2; c.880A>G, (p.Lys294Glu), has been observed in a proband with early-onset severe retinal dystrophy (VCEP member-provided data), but has been classified as a variant of uncertain significance for RPE65-related recessive retinopathy by the ClinGen LCA / eoRD VCEP, so the PM5_Supporting code is not met. In summary, this variant meets the criteria to be classified as likely benign for RPE65-related recessive retinopathy based on the ACMG/AMP criteria applied, as specified by the ClinGen LCA / eoRD VCEP: BA1 and PP3_Moderate. (VCEP specifications version 1.0.0; date of approval 09/21/2023). LINK:https://erepo.genome.network/evrepo/ui/classification/CA146043/MONDO:0100368/120

• Frequency:
  • Genomes: 𝑓 0.0025 (7 hom., cov: 32)
  • Exomes 𝑓: 0.0012 (38 hom.)
• Consequence: RPE65 NM_000329.3 missense
• Clinical Significance: Likely benign reviewed by expert panel B: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 Likely_benign. Variant got -6 ACMG points.

• PP3: For more information check the summary or visit ClinGen Evidence Repository.
• BA1: 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.881A>C	p.Lys294Thr	missense_variant	9/14	ENST00000262340.6	NP_000320.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
RPE65	ENST00000262340.6	c.881A>C	p.Lys294Thr	missense_variant	9/14	1	NM_000329.3	ENSP00000262340.5

Frequencies

GnomAD3 genomes AF: 0.00248 AC: 378 AN: 152170 Hom.: 7 Cov.: 32

Gnomad AFR AF: 0.000483

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0225

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000192

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00622

GnomAD3 exomes AF: 0.00527 AC: 1325 AN: 251234 Hom.: 30 AF XY: 0.00387 AC XY: 525 AN XY: 135778

Gnomad AFR exome AF: 0.000308

Gnomad AMR exome AF: 0.0372

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000544

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00539

GnomAD4 exome AF: 0.00119 AC: 1737 AN: 1461810 Hom.: 38 Cov.: 34 AF XY: 0.00100 AC XY: 727 AN XY: 727198

Gnomad4 AFR exome AF: 0.000239

Gnomad4 AMR exome AF: 0.0365

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000809

Gnomad4 OTH exome AF: 0.00141

GnomAD4 genome AF: 0.00248 AC: 378 AN: 152288 Hom.: 7 Cov.: 32 AF XY: 0.00230 AC XY: 171 AN XY: 74454

Gnomad4 AFR AF: 0.000481

Gnomad4 AMR AF: 0.0224

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.000193

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00616

Alfa AF: 0.000733 Hom.: 0

Bravo AF: 0.00569

ExAC AF: 0.00400 AC: 486

Asia WGS AF: 0.000289 AC: 1 AN: 3478

ClinVar

Significance: Likely benign

Submissions summary: Benign:12 Other:1

Revision: reviewed by expert panel

Submissions by phenotype

not specified Benign:3

Benign, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Oct 08, 2013	- -
Likely benign, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	May 03, 2022	- -
Benign, criteria provided, single submitter	clinical testing	GeneDx	Dec 30, 2016	This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

not provided Benign:2 Other:1

not provided, no classification provided	literature only	Retina International	-	- -
Likely benign, criteria provided, single submitter	not provided	Breakthrough Genomics, Breakthrough Genomics	-	- -
Benign, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Sep 01, 2024	RPE65: BS1, BS2 -

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

Likely benign, criteria provided, single submitter	clinical testing	Counsyl	Mar 07, 2017	- -
Benign, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Feb 01, 2024	- -

RPE65-related recessive retinopathy Benign:1

Likely benign, reviewed by expert panel

curation

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

Feb 20, 2024

NM_000329.3(RPE65):c.881A>C is a missense variant that causes substitution of lysine with threonine at position 294. This variant is present in gnomAD v.2.1.1 at a GrpMax allele frequency of 0.03554, with 1312 alleles / 35390 total alleles in the Admixed American population (with 33 homozygotes), which is higher than the ClinGen LCA / eoRD VCEP BA1 threshold of >0.008 (BA1). This variant has been reported in at least 1 proband with early-onset severe retinal dystrophy who harbored the variant in the heterozygous state (PMID: 19431183) with the NM_000329.3(RPE65):c.1078G>C (p.Ala360Pro) variant in trans and a 22-bp deletion within exon 12 in cis (PMID: 19431183). However, the proband was not counted for the PM3 or BP2 codes because the other two variants have not yet been classified by the ClinGen LCA / eoRD VCEP. The meta-predictor REVEL gives a score of 0.974, which is above the ClinGen LCA/eoRP VCEP PP3 threshold of >0.773 and predicts a damaging effect on RPE65 function (PP3_Moderate). The variant exhibited 16%-68% enzymatic activity in a retinoid isomerase assay relative to the wild-type control, which is between the ClinGen LCA / eoRD VCEP thresholds of <10% activity (PS3_Supporting) and >50% activity (BS3_Supporting), so neither functional study code is met (PMID: 16150724, PMID: 19431183). Another missense variant in the same codon, NM_000329.2; c.880A>G, (p.Lys294Glu), has been observed in a proband with early-onset severe retinal dystrophy (VCEP member-provided data), but has been classified as a variant of uncertain significance for RPE65-related recessive retinopathy by the ClinGen LCA / eoRD VCEP, so the PM5_Supporting code is not met. In summary, this variant meets the criteria to be classified as likely benign for RPE65-related recessive retinopathy based on the ACMG/AMP criteria applied, as specified by the ClinGen LCA / eoRD VCEP: BA1 and PP3_Moderate. (VCEP specifications version 1.0.0; date of approval 09/21/2023). -

Leber congenital amaurosis Benign:1

Benign, no assertion criteria provided

clinical testing

Natera, Inc.

Jun 18, 2020

- -

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

Likely benign, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Aug 16, 2021

- -

Leber congenital amaurosis 2 Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Apr 28, 2017

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). Publications were found based on this search. The evidence from the literature, in combination with allele frequency data from public databases where available, was sufficient to rule this variant out of causing disease. Therefore, this variant is classified as benign. -

Retinitis pigmentosa Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Apr 28, 2017

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). Publications were found based on this search. The evidence from the literature, in combination with allele frequency data from public databases where available, was sufficient to rule this variant out of causing disease. Therefore, this variant is classified as benign. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.82
BayesDel_addAF	Pathogenic	0.17	D
BayesDel_noAF	Pathogenic	0.50
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.97	D
Eigen	Pathogenic	0.83
Eigen_PC	Pathogenic	0.77
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Benign	0.78	T
MetaRNN	Benign	0.0088	T
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.2	M
PrimateAI	Uncertain	0.60	T
PROVEAN	Pathogenic	-4.7	D
REVEL	Pathogenic	0.97
Sift	Uncertain	0.0020	D
Sift4G	Uncertain	0.0040	D
Polyphen		1.0	D
Vest4		0.92
MVP		1.0
MPC		0.38
ClinPred		0.10	T
GERP RS		5.2
Varity_R		0.92
gMVP		0.96

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs61752901; hg19: chr1-68904742; COSMIC: COSV104574582;