rs1554519546

Positions:

• chr8-54626049-GGAGGGATACTTTGT-G

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_006269.2(RP1):​c.2172_2185delGATACTTTGTGAGG​(p.Ile725fs) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,644 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: RP1 NM_006269.2 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 2.29

Genes affected

RP1 (HGNC:10263): (RP1 axonemal microtubule associated) This gene encodes a member of the doublecortin family. The protein encoded by this gene contains two doublecortin domains, which bind microtubules and regulate microtubule polymerization. The encoded protein is a photoreceptor microtubule-associated protein and is required for correct stacking of outer segment disc. This protein and the RP1L1 protein, another retinal-specific protein, play essential and synergistic roles in affecting photosensitivity and outer segment morphogenesis of rod photoreceptors. Because of its response to in vivo retinal oxygen levels, this protein was initially named ORP1 (oxygen-regulated protein-1). This protein was subsequently designated RP1 (retinitis pigmentosa 1) when it was found that mutations in this gene cause autosomal dominant retinitis pigmentosa. Mutations in this gene also cause autosomal recessive retinitis pigmentosa. Transcript variants resulted from an alternative promoter and alternative splicings have been found, which overlap the current reference sequence and has several exons upstream and downstream of the current reference sequence. However, the biological validity and full-length nature of some variants cannot be determined at this time.[provided by RefSeq, Sep 2010]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 88 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 8-54626049-GGAGGGATACTTTGT-G is Pathogenic according to our data. Variant chr8-54626049-GGAGGGATACTTTGT-G is described in ClinVar as [Pathogenic]. Clinvar id is 437950.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr8-54626049-GGAGGGATACTTTGT-G is described in Lovd as [Pathogenic]. Variant chr8-54626049-GGAGGGATACTTTGT-G is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
RP1	NM_006269.2	c.2172_2185delGATACTTTGTGAGG	p.Ile725fs	frameshift_variant	4/4	ENST00000220676.2	NP_006260.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
RP1	ENST00000220676.2	c.2172_2185delGATACTTTGTGAGG	p.Ile725fs	frameshift_variant	4/4	1	NM_006269.2	ENSP00000220676.1
RP1	ENST00000637698.1	c.787+3766_787+3779delGATACTTTGTGAGG		intron_variant		5		ENSP00000490104.1
RP1	ENST00000636932.1	c.787+3766_787+3779delGATACTTTGTGAGG		intron_variant		5		ENSP00000489857.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461644 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 727112

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 21, 2022

For these reasons, this variant has been classified as Pathogenic. This variant disrupts a region of the RP1 protein in which other variant(s) (p.Ile2061Serfs*12 ) have been determined to be pathogenic (PMID: 11527933, 19933189, 29425069, 30027431). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. ClinVar contains an entry for this variant (Variation ID: 437950). This premature translational stop signal has been observed in individual(s) with autosomal dominant retinitis pigmentosa (PMID: 10484783, 32581362). This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Ile725Argfs*6) in the RP1 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 1432 amino acid(s) of the RP1 protein. -

Retinitis pigmentosa Pathogenic:1

Pathogenic, no assertion criteria provided

research

NIHR Bioresource Rare Diseases, University of Cambridge

Jan 01, 2015

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Computational scores

Source: dbNSFP v4.3

Splicing

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

Publications

LitVar

Other links and lift over

dbSNP: rs1554519546; hg19: chr8-55538609;