NM_130837.3:c.1681+3A>G

Variant names:

• chr3-193645628-A-G
• rs1553878573
• NM_130837.3:c.1681+3A>G

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2 PP3 PP5

The NM_130837.3(OPA1):​c.1681+3A>G variant causes a splice region, intron change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency: Genomes: not found (cov: 33)
• Consequence: OPA1 NM_130837.3 splice_region, intron
• Scores: Splicing: ADA: 0.9991
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:4
• Conservation: PhyloP100: 6.45
• Publications: 0 publications found

Genes affected

OPA1 (HGNC:8140): (OPA1 mitochondrial dynamin like GTPase) The protein encoded by this gene is a nuclear-encoded mitochondrial protein with similarity to dynamin-related GTPases. The encoded protein localizes to the inner mitochondrial membrane and helps regulate mitochondrial stability and energy output. This protein also sequesters cytochrome c. Mutations in this gene have been associated with optic atrophy type 1, which is a dominantly inherited optic neuropathy resulting in progressive loss of visual acuity, leading in many cases to legal blindness. [provided by RefSeq, Aug 2017]

OPA1 Gene-Disease associations (from GenCC):

• autosomal dominant optic atrophy, classic form

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, Ambry Genetics
• optic atrophy

  Inheritance: AD Classification: DEFINITIVE Submitted by: G2P
• optic atrophy with or without deafness, ophthalmoplegia, myopathy, ataxia, and neuropathy

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae), G2P
• OPA1-related optic atrophy with or without extraocular features

  Inheritance: SD Classification: DEFINITIVE Submitted by: ClinGen
• Behr syndrome

  Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
• mitochondrial DNA depletion syndrome 14 (cardioencephalomyopathic type)

  Inheritance: AR Classification: STRONG, LIMITED Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
• Leigh syndrome

  Inheritance: AR Classification: MODERATE Submitted by: ClinGen
• autosomal dominant optic atrophy plus syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ENSG00000306963 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 3-193645628-A-G is Pathogenic according to our data. Variant chr3-193645628-A-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 447895.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
OPA1	NM_130837.3	c.1681+3A>G		splice_region_variant, intron_variant	Intron 17 of 30	ENST00000361510.8	NP_570850.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
OPA1	ENST00000361510.8	c.1681+3A>G		splice_region_variant, intron_variant	Intron 17 of 30	5	NM_130837.3	ENSP00000355324.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 33

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:4

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Pathogenic:1 Uncertain:2

Jul 01, 2017

CeGaT Center for Human Genetics Tuebingen

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Feb 17, 2023

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Non-canonical splice site variant demonstrated to result in loss of function (Weisschuh et al., 2021); In silico analysis supports a deleterious effect on splicing; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 34242285) -

Jan 30, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change falls in intron 15 of the OPA1 gene. It does not directly change the encoded amino acid sequence of the OPA1 protein. It affects a nucleotide within the consensus splice site of the intron. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with OPA1-related conditions. ClinVar contains an entry for this variant (Variation ID: 447895). Nucleotide substitutions within the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site, but this prediction has not been confirmed by published transcriptional studies. 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. -

not specified Uncertain:1

Nov 18, 2016

Athena Diagnostics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Optic atrophy Uncertain:1

Jan 01, 2020

Institute of Human Genetics, Univ. Regensburg, Univ. Regensburg

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.20
CADD	Benign	19
DANN	Benign	0.97
PhyloP100		6.5

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.96
SpliceAI score (max)		0.51		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.51		Position offset: -3

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

Other links and lift over

dbSNP: rs1553878573; hg19: chr3-193363417;