X-46837101-A-T

Variant names:

• chrX-46837101-A-T
• NM_006915.3:c.1A>T

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PVS1_Supporting PM2 PP5_Moderate

The NM_006915.3(RP2):​c.1A>T​(p.Met1?) variant causes a initiator codon 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 (★).

• Frequency: Genomes: not found (cov: 24)
• Consequence: RP2 NM_006915.3 initiator_codon
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 4.30

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 Uncertain_significance. Variant got 5 ACMG points.

• PVS1: Start lost variant, no pathogenic variants between lost start and next in-frame start position. Next in-frame start position is after 41 codons. Genomic position: 46853494. Lost 0.115 part of the original CDS.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant X-46837101-A-T is Pathogenic according to our data. Variant chrX-46837101-A-T is described in ClinVar as [Pathogenic]. Clinvar id is 2097576.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
RP2	NM_006915.3	c.1A>T	p.Met1?	initiator_codon_variant	Exon 1 of 5	ENST00000218340.4	NP_008846.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
RP2	ENST00000218340.4	c.1A>T	p.Met1?	initiator_codon_variant	Exon 1 of 5	1	NM_006915.3	ENSP00000218340.3

Frequencies

GnomAD3 genomes Cov.: 24

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 24

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:1

Feb 08, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change affects the initiator methionine of the RP2 mRNA. The next in-frame methionine is located at codon 41. This variant is not present in population databases (gnomAD no frequency). Disruption of the initiator codon has been observed in individuals with retinitis pigmentosa (PMID: 26355662, 29847639). ClinVar contains an entry for this variant (Variation ID: 2097576). This variant disrupts a region of the RP2 protein in which other variant(s) (p.Ser6del) have been determined to be pathogenic (PMID: 9697692, 10942419, 17724181, 28209709; Invitae). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Retinitis pigmentosa 2 Pathogenic:1

Jan 04, 2024

3billion

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The variant is not observed in the gnomAD v2.1.1 dataset. Predicted Consequence/Location: Start-lost: reinitiation of translation may occur at a downstream alternate start codon but still result in a loss or disruption of normal protein function as there have been pathogenic variants reported upstream of the alternate start codon. The variant has been reported to be associated with RP2 related disorder (ClinVar ID: VCV002097576). Therefore, this variant is classified as Likely pathogenic according to the recommendation of ACMG/AMP guideline. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Pathogenic	0.58
CADD	Uncertain	24
DANN	Benign	0.96
DEOGEN2	Benign	0.24	T
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.90	D
M_CAP	Pathogenic	0.97	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Uncertain	0.69	D
PROVEAN	Benign	-2.0	N
REVEL	Pathogenic	0.85
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.88
MutPred		0.97		Loss of catalytic residue at M1 (P = 0.007);
MVP		1.0
ClinPred		0.99	D
GERP RS		3.5
Varity_R		0.91
gMVP		0.73

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

No publications associated with this variant yet.

Other links and lift over

hg19: chrX-46696536;