chr1-12001423-G-A

Variant names:

Variant summary

Our verdict is Pathogenic. Variant got 19 ACMG points: 19P and 0B. PM1PM2PM5PP2PP3_StrongPP5_Very_Strong

The NM_014874.4(MFN2):c.839G>A(p.Arg280His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,472 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R280C) has been classified as Likely pathogenic.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

MFN2
NM_014874.4 missense

Scores

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:15

Conservation

PhyloP100: 9.60

Variant links:

Genes affected

MFN2 (HGNC:16877): (mitofusin 2) This gene encodes a mitochondrial membrane protein that participates in mitochondrial fusion and contributes to the maintenance and operation of the mitochondrial network. This protein is involved in the regulation of vascular smooth muscle cell proliferation, and it may play a role in the pathophysiology of obesity. Mutations in this gene cause Charcot-Marie-Tooth disease type 2A2, and hereditary motor and sensory neuropathy VI, which are both disorders of the peripheral nervous system. Defects in this gene have also been associated with early-onset stroke. Two transcript variants encoding the same protein have been identified. [provided by RefSeq, Jul 2008]

MFN2 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 19 ACMG points.

PM1

In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 11 uncertain in NM_014874.4

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr1-12001422-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 245809.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

PP2

Missense variant in the MFN2 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 123 curated pathogenic missense variants (we use a threshold of 10). The gene has 23 curated benign missense variants. Gene score misZ: 1.6575 (below the threshold of 3.09). Trascript score misZ: 3.2174 (above the threshold of 3.09). GenCC associations: The gene is linked to Charcot-Marie-Tooth disease type 2A2, axonal hereditary motor and sensory neuropathy, hereditary motor and sensory neuropathy type 6, Charcot-Marie-Tooth disease, axonal, autosomal recessive, type 2a2b;, multiple symmetric lipomatosis, severe early-onset axonal neuropathy due to MFN2 deficiency.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.983

PP5

Variant 1-12001423-G-A is Pathogenic according to our data. Variant chr1-12001423-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 2271.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr1-12001423-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MFN2	NM_014874.4 link	c.839G>A	p.Arg280His	missense_variant	Exon 9 of 19	ENST00000235329.10	NP_055689.1	O95140-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MFN2	ENST00000235329.10 link	c.839G>A	p.Arg280His	missense_variant	Exon 9 of 19	1	NM_014874.4	ENSP00000235329.5		O95140-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000400

AC:

AN:

250290

Hom.:

AF XY:

0.00

AC XY:

AN XY:

135432

show subpopulations

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 SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000884

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000205

AC:

AN:

1461472

Hom.:

Cov.:

AF XY:

0.00000275

AC XY:

AN XY:

727024

show subpopulations

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:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000180

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

ExAC

AF:

0.00000824

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000594

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:15

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Charcot-Marie-Tooth disease type 2A2

Pathogenic:6

Aug 01, 2006

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Jul 20, 2021

Laboratório de Neurologia Aplicada e Experimental, Faculdade de Medicina de Ribeirao Preto – Universidade de Sao Paulo

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: research

- -

Dec 07, 2021

MGZ Medical Genetics Center

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Feb 23, 2023

3billion, Medical Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The variant is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: <0.001%). Missense changes are a common disease-causing mechanism. In silico tool predictions suggest damaging effect of the variant on gene or gene product (REVEL: 0.92; 3Cnet: 0.97). Same nucleotide change resulting in same amino acid change (ClinVar ID: VCV000002271) and different missense changes at the same codon (p.Arg280Cys, p.Arg280Pro / ClinVar ID: VCV000245809, VCV000801444) have been previously reported as pathogenic/likely pathogenic with strong evidence. Therefore, this variant is classified as Pathogenic according to the recommendation of ACMG/AMP guideline. -

Jun 01, 2022

Solve-RD Consortium

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: provider interpretation

Variant confirmed as disease-causing by referring clinical team -

May 22, 2024

Neurogenomics Lab, Neuroscience Institute, University Of Cape Town

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: research

PM2_supporting: The highest population allele frequency in gnomAD v4.0 is 0.00001160 (0.001%; 1/86188 alleles) in South asian population and 0.000001799 (0.0001%; 2/1111878) in the European non-Finnish population. PP1_strong: variant segregates with =3 informative meioses across =1 family (PMID: 16835246, 16714318, 24957169). PM1 met: variant occurs in the dynamin-like GTPase domain together with other pathogenic variants. PP3_moderate: Revel score is 0.92. PS3_supporting: functional studies provide supportive evidence that this variant has a damaging effect on the gene or gene product (PMID 17296794, PMID 17215403). PS4 met: variant identified in = 10 unrelated probands with consistent phenotype for disorder. PM5 met: MFN2 p.Arg280Pro classified as likely pathogenic. -

not provided

Pathogenic:4

Mar 27, 2023

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Published functional studies show that R280H alters mitochondrial fusion (Detmer et al., 2007); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 16835246, 22492563, 21149811, 17296794, 31832804, 32657593, 35153971, 30340945, 16714318, 19584314, 17215403, 10732809, 28286897, 27549087, 27863451, 28660751, 24957169, 27027447, 27088055, 30219582, 31211173, 31827005, 15064763, 33136338, 32376792, 35418194, 24863639) -

Oct 23, 2020

Institute of Medical Genetics and Applied Genomics, University Hospital Tübingen

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jul 01, 2021

CeGaT Center for Human Genetics Tuebingen

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Sep 27, 2022

Athena Diagnostics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The frequency of this variant in the general population is consistent with pathogenicity. (Genome Aggregation Database (gnomAD), Cambridge, MA (URL: http://gnomad.broadinstitute.org)) This variant has been identified in multiple unrelated individuals with clinical features associated with Charcot-Marie-Tooth disease and appears to be associated with disease in at least one family. This variant appears to occur de novo in multiple individuals with clinical features associated with Charcot-Marie-Tooth disease. Assessment of experimental evidence suggests this variant results in abnormal protein function. This variant inhibited mitochondrial fusion and caused abnormal clustering (PMID: 17215403, 17296794). The variant is located in a region that is considered important for protein function and/or structure. -

Charcot-Marie-Tooth disease

Pathogenic:2

Inherited Neuropathy Consortium

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Molecular Genetics Laboratory, London Health Sciences Centre

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Peripheral neuropathy

Pathogenic:1

Jul 10, 2021

Kariminejad - Najmabadi Pathology & Genetics Center

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Charcot-Marie-Tooth disease type 2

Pathogenic:1

Dec 18, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 280 of the MFN2 protein (p.Arg280His). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This missense change has been observed in individuals with Charcot-Marie-Tooth disease (PMID: 15064763, 16835246, 24957169, 27088055, 27549087). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 2271). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed for this missense variant. However, the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on MFN2 protein function. Experimental studies have shown that this missense change affects MFN2 function (PMID: 17215403, 17296794). For these reasons, this variant has been classified as Pathogenic. -

Neuropathy, hereditary motor and sensory, type 6A

Pathogenic:1

Jun 28, 2022

Institute of Human Genetics Munich, Klinikum Rechts Der Isar, TU München

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.91

BayesDel_addAF

Pathogenic

0.55

BayesDel_noAF

Pathogenic

0.55

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Uncertain

0.74

D;D

Eigen

Pathogenic

0.88

Eigen_PC

Pathogenic

0.82

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Pathogenic

0.99

D;.

M_CAP

Pathogenic

0.36

MetaRNN

Pathogenic

0.98

D;D

MetaSVM

Pathogenic

1.1

MutationAssessor

Pathogenic

3.2

M;M

PrimateAI

Uncertain

0.71

PROVEAN

Pathogenic

-4.7

D;D

REVEL

Pathogenic

0.92

Sift

Pathogenic

0.0

D;D

Sift4G

Uncertain

0.0040

D;D

Polyphen

1.0

D;D

Vest4

0.93

MutPred

0.91

Gain of helix (P = 0.0696);Gain of helix (P = 0.0696);

MVP

0.97

MPC

1.6

ClinPred

1.0

GERP RS

5.2

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.86

gMVP

0.93

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over