1-68448644-G-C

Variant names:

• chr1-68448644-G-C
• rs199683808
• NM_000329.3:c.74C>G

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PM1 PM2 PM5 PP2 PP3_Moderate

The NM_000329.3(RPE65):​c.74C>G​(p.Pro25Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000658 in 151,932 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P25L) has been classified as Pathogenic.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 30)
• Consequence: RPE65 NM_000329.3 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 9.59
• Publications: 15 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: Likely_pathogenic. The variant received 9 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 13 uncertain in NM_000329.3
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr1-68448644-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 437985.Status of the report is reviewed_by_expert_panel, 3 stars.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 97 curated pathogenic missense variants (we use a threshold of 10). The gene has 15 curated benign missense variants. Gene score misZ: -0.24008 (below the threshold of 3.09). Trascript score misZ: 0.28272 (below the threshold of 3.09). GenCC associations: The gene is linked to Leber congenital amaurosis 2, retinitis pigmentosa 87 with choroidal involvement, Leber congenital amaurosis, RPE65-related recessive retinopathy, retinitis pigmentosa, retinitis pigmentosa 20, RPE65-related dominant retinopathy, severe early-childhood-onset retinal dystrophy.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.923

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000329.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	RPE65	NM_000329.3	MANE Select	c.74C>G	p.Pro25Arg	missense	Exon 2 of 14	NP_000320.1
	RPE65	NM_001406853.1		c.74C>G	p.Pro25Arg	missense	Exon 2 of 13	NP_001393782.1
	RPE65	NM_001406859.1		c.74C>G	p.Pro25Arg	missense	Exon 2 of 10	NP_001393788.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	RPE65	ENST00000262340.6	TSL:1 MANE Select	c.74C>G	p.Pro25Arg	missense	Exon 2 of 14	ENSP00000262340.5
	RPE65	ENST00000713936.1		n.74C>G		non_coding_transcript_exon	Exon 2 of 15	ENSP00000519233.1
	RPE65	ENST00000713937.1		n.74C>G		non_coding_transcript_exon	Exon 2 of 13	ENSP00000519234.1

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 151932 Hom.: 0 Cov.: 30

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000656

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: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 32

GnomAD4 genome AF: 0.00000658 AC: 1 AN: 151932 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 74166

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 41344

American (AMR) AF: 0.0000656 AC: 1 AN: 15244

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5162

South Asian (SAS) AF: 0.00 AC: 0 AN: 4810

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10582

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68002

Other (OTH) AF: 0.00 AC: 0 AN: 2090

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.00 Hom.: 0

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.30
BayesDel_addAF	Pathogenic	0.48	D
BayesDel_noAF	Pathogenic	0.46
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.95	D
Eigen	Pathogenic	0.78
Eigen_PC	Pathogenic	0.69
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.89	D
M_CAP	Pathogenic	0.38	D
MetaRNN	Pathogenic	0.92	D
MetaSVM	Pathogenic	0.97	D
MutationAssessor	Pathogenic	3.4	M
PhyloP100		9.6
PrimateAI	Uncertain	0.65	T
PROVEAN	Pathogenic	-6.5	D
REVEL	Pathogenic	0.85
Sift	Uncertain	0.0020	D
Sift4G	Uncertain	0.0040	D
Polyphen		1.0	D
Vest4		0.92
MutPred		0.58		Gain of solvent accessibility (P = 0.0411)
MVP		1.0
MPC		0.35
ClinPred		0.99	D
GERP RS		5.3
Varity_R		0.81
gMVP		0.88
Mutation Taster		=28/72	disease causing

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

Other links and lift over

dbSNP: rs199683808; hg19: chr1-68914327;