1-68439224-G-C

Variant names:

• chr1-68439224-G-C
• rs988133284
• NM_000329.3:c.825C>G

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000329.3(RPE65):​c.825C>G​(p.Tyr275*) variant causes a stop gained change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. Y275Y) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: RPE65 NM_000329.3 stop_gained
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:5
• Conservation: PhyloP100: 3.74
• Publications: 2 publications found

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]

RPE65 Gene-Disease associations (from GenCC):

• retinitis pigmentosa

  Inheritance: AD, AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, G2P
• Leber congenital amaurosis 2

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae)
• RPE65-related recessive retinopathy

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen, Ambry Genetics
• RPE65-related dominant retinopathy

  Inheritance: AD Classification: STRONG Submitted by: ClinGen
• retinitis pigmentosa 20

  Inheritance: AR, AD Classification: STRONG, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
• Leber congenital amaurosis

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• severe early-childhood-onset retinal dystrophy

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• retinitis pigmentosa 87 with choroidal involvement

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics

LOC124904198 (HGNC:):

ACMG classification

Our verdict: Pathogenic. The variant received 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 1-68439224-G-C is Pathogenic according to our data. Variant chr1-68439224-G-C is described in ClinVar as Pathogenic. ClinVar VariationId is 587393.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
RPE65	NM_000329.3	c.825C>G	p.Tyr275*	stop_gained	Exon 8 of 14	ENST00000262340.6	NP_000320.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
RPE65	ENST00000262340.6	c.825C>G	p.Tyr275*	stop_gained	Exon 8 of 14	1	NM_000329.3	ENSP00000262340.5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Leber congenital amaurosis 2;C3151086:Retinitis pigmentosa 20 Pathogenic:1

May 06, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Tyr275*) in the RPE65 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in RPE65 are known to be pathogenic (PMID: 9326941, 9501220, 9843205, 18632300). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individuals with inherited retinal dystrophy (PMID: 30576320, 31273949, 31630094). ClinVar contains an entry for this variant (Variation ID: 587393). 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.

Leber congenital amaurosis 2 Pathogenic:1

Jan 08, 2024

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Retinal dystrophy Pathogenic:1

Jan 01, 2019

Institute of Human Genetics, Univ. Regensburg, Univ. Regensburg

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Congenital isolated adrenocorticotropic hormone deficiency Pathogenic:1

Aug 21, 2018

Molecular Genetics Laboratory, Institute for Ophthalmic Research

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: research

Retinitis pigmentosa Pathogenic:1

Oct 25, 2021

Institute of Medical Genetics and Applied Genomics, University Hospital Tübingen

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.63
CADD	Pathogenic	38
DANN	Uncertain	1.0
Eigen	Pathogenic	0.71
Eigen_PC	Uncertain	0.57
FATHMM_MKL	Uncertain	0.96	D
PhyloP100		3.7
Vest4		0.94
GERP RS		3.6
Mutation Taster		=2/198	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.080		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs988133284; hg19: chr1-68904907;