1-68448644-G-T

Variant names:

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

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>A​(p.Pro25Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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: not found (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, 0.919

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
RPE65	NM_000329.3	c.74C>A	p.Pro25Gln	missense_variant	Exon 2 of 14	ENST00000262340.6	NP_000320.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
RPE65	ENST00000262340.6	c.74C>A	p.Pro25Gln	missense_variant	Exon 2 of 14	1	NM_000329.3	ENSP00000262340.5

Frequencies

GnomAD3 genomes Cov.: 30

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 30

Alfa AF: 0.00 Hom.: 0

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.27
BayesDel_addAF	Pathogenic	0.36	D
BayesDel_noAF	Pathogenic	0.28
CADD	Pathogenic	27
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.95	D
Eigen	Pathogenic	0.79
Eigen_PC	Pathogenic	0.69
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.88	D
M_CAP	Pathogenic	0.37	D
MetaRNN	Pathogenic	0.92	D
MetaSVM	Pathogenic	0.99	D
MutationAssessor	Pathogenic	3.4	M
PhyloP100		9.6
PrimateAI	Uncertain	0.59	T
PROVEAN	Pathogenic	-5.8	D
REVEL	Pathogenic	0.84
Sift	Uncertain	0.0020	D
Sift4G	Uncertain	0.0030	D
Vest4		0.87
ClinPred		1.0	D
GERP RS		5.3
Varity_R		0.70
gMVP		0.86
Mutation Taster		=26/74	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; COSMIC: COSV52013336;