6-42704609-C-G

Variant names:

• chr6-42704609-C-G
• rs121918567
• NM_000322.5:c.584G>C

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM1 PM5 PP2 PP3_Moderate

The NM_000322.5(PRPH2):​c.584G>C​(p.Arg195Pro) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000479 in 1,461,870 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 1/1 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R195Q) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000048 (0 hom.)
• Consequence: PRPH2 NM_000322.5 missense, splice_region
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 7.85
• Publications: 25 publications found

Genes affected

PRPH2 (HGNC:9942): (peripherin 2) The protein encoded by this gene is a member of the transmembrane 4 superfamily, also known as the tetraspanin family. Most of these members are cell-surface proteins that are characterized by the presence of four hydrophobic domains. The proteins mediate signal transduction events that play a role in the regulation of cell development, activation, growth and motility. This encoded protein is a cell surface glycoprotein found in the outer segment of both rod and cone photoreceptor cells. It may function as an adhesion molecule involved in stabilization and compaction of outer segment disks or in the maintenance of the curvature of the rim. This protein is essential for disk morphogenesis. Defects in this gene are associated with both central and peripheral retinal degenerations. Some of the various phenotypically different disorders are autosomal dominant retinitis pigmentosa, progressive macular degeneration, macular dystrophy and retinitis pigmentosa digenic. [provided by RefSeq, Jul 2008]

PRPH2 Gene-Disease associations (from GenCC):

• hereditary macular dystrophy

  Inheritance: AD Classification: DEFINITIVE Submitted by: G2P
• PRPH2-related retinopathy

  Inheritance: AD Classification: DEFINITIVE Submitted by: Ambry Genetics
• Leber congenital amaurosis

  Inheritance: AR Classification: DEFINITIVE Submitted by: G2P
• retinitis pigmentosa 7

  Inheritance: AR, SD, AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P
• inherited retinal dystrophy

  Inheritance: SD, AR Classification: DEFINITIVE, MODERATE Submitted by: ClinGen, Ambry Genetics
• choroidal dystrophy, central areolar 2

  Inheritance: AD Classification: STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
• fundus albipunctatus

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• vitelliform macular dystrophy 3

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• adult-onset foveomacular vitelliform dystrophy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• central areolar choroidal dystrophy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• cone-rod dystrophy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• multifocal pattern dystrophy simulating fundus flavimaculatus

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• patterned macular dystrophy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• retinitis pigmentosa

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• retinitis punctata albescens

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

• PM1: In a hotspot region, there are 10 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 11 uncertain in NM_000322.5
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr6-42704609-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 623212.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 126 curated pathogenic missense variants (we use a threshold of 10). The gene has 10 curated benign missense variants. Gene score misZ: 0.10182 (below the threshold of 3.09). Trascript score misZ: 0.57529 (below the threshold of 3.09). GenCC associations: The gene is linked to inherited retinal dystrophy, fundus albipunctatus, retinitis pigmentosa 7, choroidal dystrophy, central areolar 2, adult-onset foveomacular vitelliform dystrophy, retinitis punctata albescens, hereditary macular dystrophy, central areolar choroidal dystrophy, Leber congenital amaurosis, vitelliform macular dystrophy 3, multifocal pattern dystrophy simulating fundus flavimaculatus, PRPH2-related retinopathy, cone-rod dystrophy, retinitis pigmentosa, patterned macular dystrophy.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.899

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000322.5. 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
	PRPH2	NM_000322.5	MANE Select	c.584G>C	p.Arg195Pro	missense splice_region	Exon 2 of 3	NP_000313.2

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PRPH2	ENST00000230381.7	TSL:1 MANE Select	c.584G>C	p.Arg195Pro	missense splice_region	Exon 2 of 3	ENSP00000230381.5

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 0.00000479 AC: 7 AN: 1461870 Hom.: 0 Cov.: 32 AF XY: 0.00000413 AC XY: 3 AN XY: 727236

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86244

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53414

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000629 AC: 7 AN: 1112012

Other (OTH) AF: 0.00 AC: 0 AN: 60394

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

PRPH2-related disorder Uncertain:1

Nov 27, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with proline, which is neutral and non-polar, at codon 195 of the PRPH2 protein (p.Arg195Pro). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with PRPH2-related conditions. ClinVar contains an entry for this variant (Variation ID: 866845). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. This variant disrupts the p.Arg195 amino acid residue in PRPH2. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 14557183, 20213611; Invitae). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance.

Retinal dystrophy Uncertain:1

Nov 05, 2018

Blueprint Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.23	D
BayesDel_noAF	Uncertain	0.090
CADD	Pathogenic	33
DANN	Uncertain	1.0
Eigen	Uncertain	0.66
Eigen_PC	Pathogenic	0.67
FATHMM_MKL	Uncertain	0.95	D
M_CAP	Uncertain	0.15	D
MetaRNN	Pathogenic	0.90	D
MetaSVM	Benign	-1.1	T
PhyloP100		7.9
PrimateAI	Pathogenic	0.88	D
PROVEAN	Uncertain	-4.3	D
REVEL	Uncertain	0.60
Sift	Uncertain	0.0010	D
Sift4G	Uncertain	0.043	D
Vest4		0.90
MutPred		0.73		Loss of MoRF binding (P = 0.0467)
MVP		0.55
MPC		1.2
ClinPred		1.0	D
GERP RS		5.1
gMVP		0.96
Mutation Taster		=17/83	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: rs121918567; hg19: chr6-42672347;