X-46853726-G-C

Position:

• chrX-46853726-G-C

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1 PM2 PP3_Strong

The NM_006915.3(RP2):​c.353G>C​(p.Arg118Pro) 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. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 23)
• Consequence: RP2 NM_006915.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.45

Genes affected

RP2 (HGNC:10274): (RP2 activator of ARL3 GTPase) The RP2 locus has been implicated as one cause of X-linked retinitis pigmentosa. The predicted gene product shows homology with human cofactor C, a protein involved in the ultimate step of beta-tubulin folding. Progressive retinal degeneration may therefore be due to the accumulation of incorrectly-folded photoreceptor or neuron-specific tubulin isoforms followed by progressive cell death [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PM1: In a domain C-CAP/cofactor C-like (size 155) in uniprot entity XRP2_HUMAN there are 5 pathogenic changes around while only 1 benign (83%) in NM_006915.3
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.994

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
RP2	NM_006915.3	c.353G>C	p.Arg118Pro	missense_variant	2/5	ENST00000218340.4	NP_008846.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
RP2	ENST00000218340.4	c.353G>C	p.Arg118Pro	missense_variant	2/5	1	NM_006915.3	ENSP00000218340.3

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 23

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Feb 23, 2021

This variant is not present in population databases (ExAC no frequency). 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. This variant disrupts the p.Arg118 amino acid residue in RP2. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 10520237, 20021257, 21738648, 22072390). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has been observed in individual(s) with retinitis pigmentosa (Invitae). This sequence change replaces arginine with proline at codon 118 of the RP2 protein (p.Arg118Pro). The arginine residue is highly conserved and there is a moderate physicochemical difference between arginine and proline. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.62	D
BayesDel_noAF	Pathogenic	0.66
CADD	Pathogenic	32
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.92	D
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.98	D
M_CAP	Pathogenic	0.79	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	3.4	M
PrimateAI	Uncertain	0.76	T
PROVEAN	Pathogenic	-7.0	D
REVEL	Pathogenic	0.95
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.99
MutPred		0.92		Loss of sheet (P = 0.0457);
MVP		1.0
MPC		1.2
ClinPred		1.0	D
GERP RS		5.6
Varity_R		1.0
gMVP		0.98

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: rs28933687; hg19: chrX-46713161;