chr19-45584618-C-G

Variant names:

• chr19-45584618-C-G
• rs1250409781
• NM_025136.4:c.142+5G>C

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM2 PP3_Moderate PP5

The NM_025136.4(OPA3):​c.142+5G>C variant causes a splice region, intron change. The variant allele was found at a frequency of 0.00000274 in 1,461,876 control chromosomes in the GnomAD database, with no homozygous occurrence. 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: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: OPA3 NM_025136.4 splice_region, intron
• Scores: Splicing: ADA: 0.9999
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:4
• Conservation: PhyloP100: 5.25
• Publications: 2 publications found

Genes affected

OPA3 (HGNC:8142): (outer mitochondrial membrane lipid metabolism regulator OPA3) The mouse ortholog of this protein co-purifies with the mitochondrial inner membrane. Mutations in this gene have been shown to result in 3-methylglutaconic aciduria type III and autosomal dominant optic atrophy and cataract. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Oct 2009]

OPA3 Gene-Disease associations (from GenCC):

• optic atrophy 3

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Labcorp Genetics (formerly Invitae), Orphanet
• 3-methylglutaconic aciduria type 3

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Myriad Women’s Health, G2P, Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Uncertain_significance. The variant received 5 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 19-45584618-C-G is Pathogenic according to our data. Variant chr19-45584618-C-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 553096.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
OPA3	NM_025136.4	c.142+5G>C		splice_region_variant, intron_variant	Intron 1 of 1	ENST00000263275.5	NP_079412.1
OPA3	NM_001017989.3	c.142+5G>C		splice_region_variant, intron_variant	Intron 1 of 1		NP_001017989.2
OPA3	XM_006723403.5	c.-158+5G>C		splice_region_variant, intron_variant	Intron 1 of 2		XP_006723466.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
OPA3	ENST00000263275.5	c.142+5G>C		splice_region_variant, intron_variant	Intron 1 of 1	1	NM_025136.4	ENSP00000263275.4
OPA3	ENST00000323060.4	c.142+5G>C		splice_region_variant, intron_variant	Intron 1 of 1	1		ENSP00000319817.3
OPA3	ENST00000544371.1	c.-18+17477G>C		intron_variant	Intron 1 of 1	2		ENSP00000442839.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251248 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461876 Hom.: 0 Cov.: 32 AF XY: 0.00000275 AC XY: 2 AN XY: 727238

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.0000464 AC: 4 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111996

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2 Uncertain:4

Revision: criteria provided, conflicting classifications

Submissions by phenotype

3-Methylglutaconic aciduria type 3 Uncertain:4

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Suma Genomics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

-

Neuberg Centre For Genomic Medicine, NCGM

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The OPA3 c.142+5G>C variant has been reported in compond heterozygous state in individuals affected with 3-methylglutaconic aciduria, type III (Christina et. al., 2014). The c.142+5G>C variant is novel (not in any individuals) in 1000 Genomes and has allele frequency of 0.0004% in gnomAD database. This variant has been reported to the ClinVar database as Likely pathogenic and Uncertain Significance. The variant does not affect an invariant splice nucleotide and in the absence of functional studies, this variant has been classified as Variant of Uncertain Significance (VUS). -

Nov 12, 2020

Kasturba Medical College, Manipal, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Aug 02, 2017

Counsyl

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

3-Methylglutaconic aciduria type 3;C1833809:Optic atrophy 3 Pathogenic:2

Jul 13, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. Variants that disrupt 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. ClinVar contains an entry for this variant (Variation ID: 553096). This variant has been observed in individual(s) with OPA3-related 3-methylglutaconic aciduria (PMID: 24749080). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. It has also been observed to segregate with disease in related individuals. This variant is present in population databases (no rsID available, gnomAD 0.003%). This sequence change falls in intron 1 of the OPA3 gene. It does not directly change the encoded amino acid sequence of the OPA3 protein. It affects a nucleotide within the consensus splice site. -

Jun 12, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.14
CADD	Uncertain	24
DANN	Benign	0.97
PhyloP100		5.2
PromoterAI		-0.62	Under-expression
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Mutation Taster		=18/82	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.98
SpliceAI score (max)		0.72		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.38		Position offset: -49
DS_DL_spliceai		0.72		Position offset: 5

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

Other links and lift over

dbSNP: rs1250409781; hg19: chr19-46087876;