X-46853725-CGT-TGC

Variant names:

• chrX-46853725-CGT-TGC
• NM_006915.3:c.352_354delCGTinsTGC
• RP2 p.Arg118Cys

Variant summary

Our verdict is Pathogenic. The variant received 13 ACMG points: 13P and 0B. PS1_Very_Strong PM1 PM5 PP3

The NM_006915.3(RP2):​c.352_354delCGTinsTGC​(p.Arg118Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. It is difficult to determine the true allele frequency of this variant because it is of type MNV, and the frequency of such variant types in population databases may be underestimated and unreliable. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another nucleotide change resulting in the same amino acid substitution has been previously reported as Likely pathogenic in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R118G) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 23)
• Consequence: RP2 NM_006915.3 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 9.45
• Publications: 0 publications found

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]

RP2 Gene-Disease associations (from GenCC):

• retinitis pigmentosa 2

  Inheritance: XL Classification: DEFINITIVE, STRONG Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae), G2P
• RP2-related retinopathy

  Inheritance: XL Classification: DEFINITIVE Submitted by: ClinGen
• retinitis pigmentosa

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 13 ACMG points.

• PS1: Transcript NM_006915.3 (RP2) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in ClinVar.
• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 uncertain in NM_006915.3
• PM5: Other missense variant is known to change same aminoacid residue: Variant chrX-46853725-C-G is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 636097.Status of the report is no_assertion_criteria_provided, 0 stars.
• PP3: No computational evidence supports a deleterious effect, but strongly conserved according to phyloP

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_006915.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	RP2	NM_006915.3	MANE Select	c.352_354delCGTinsTGC	p.Arg118Cys	missense	N/A	NP_008846.2	O75695

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	RP2	ENST00000218340.4	TSL:1 MANE Select	c.352_354delCGTinsTGC	p.Arg118Cys	missense	N/A	ENSP00000218340.3	O75695
	RP2	ENST00000891112.1		c.352_354delCGTinsTGC	p.Arg118Cys	missense	N/A	ENSP00000561171.1
	RP2	ENST00000949778.1		c.103-6263_103-6261delCGTinsTGC		intron	N/A	ENSP00000619837.1

Frequencies

GnomAD3 genomes Cov.: 23

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 23

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		9.4

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

hg19: chrX-46713160;