NM_014874.4:c.1987C>T

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 1P and 0B. PP2

The NM_014874.4(MFN2):c.1987C>T(p.Arg663Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000138 in 1,614,192 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R663H) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00014 ( 0 hom., cov: 33)

Exomes 𝑓: 0.00014 ( 0 hom. )

Consequence

MFN2
NM_014874.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:6B:2

Conservation

PhyloP100: 0.782

Publications

7 publications found

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 Gene-Disease associations (from GenCC):

neuropathy, hereditary motor and sensory, type 6A
Inheritance: AD Classification: DEFINITIVE Submitted by: G2P
Charcot-Marie-Tooth disease, axonal, autosomal recessive, type 2a2b;
Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
axonal hereditary motor and sensory neuropathy
Inheritance: SD Classification: DEFINITIVE Submitted by: ClinGen
Charcot-Marie-Tooth disease type 2A2
Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae)
hereditary motor and sensory neuropathy type 6
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
multiple symmetric lipomatosis
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
severe early-onset axonal neuropathy due to MFN2 deficiency
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

MFN2 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

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, Charcot-Marie-Tooth disease, axonal, autosomal recessive, type 2a2b;, severe early-onset axonal neuropathy due to MFN2 deficiency, hereditary motor and sensory neuropathy type 6, axonal hereditary motor and sensory neuropathy, multiple symmetric lipomatosis, neuropathy, hereditary motor and sensory, type 6A.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MFN2	NM_014874.4 link	c.1987C>T	p.Arg663Cys	missense_variant	Exon 17 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.1987C>T	p.Arg663Cys	missense_variant	Exon 17 of 19	1	NM_014874.4	ENSP00000235329.5		O95140-1

Frequencies

GnomAD3 genomes

AF:

0.000145

AC:

AN:

152246

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00317

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000621

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000118

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.000175

AC:

AN:

251412

AF XY:

0.000213

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00188

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000528

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.000137

AC:

201

AN:

1461828

Hom.:

Cov.:

AF XY:

0.000164

AC XY:

119

AN XY:

727228

show subpopulations

African (AFR)

AF:

0.0000597

AC:

AN:

33480

American (AMR)

AF:

0.0000224

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00256

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.000348

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53356

Middle Eastern (MID)

AF:

0.000173

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.0000764

AC:

AN:

1112010

Other (OTH)

AF:

0.000248

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.469

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.000144

AC:

AN:

152364

Hom.:

Cov.:

AF XY:

0.000175

AC XY:

AN XY:

74498

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41600

American (AMR)

AF:

0.00

AC:

AN:

15308

Ashkenazi Jewish (ASJ)

AF:

0.00317

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5186

South Asian (SAS)

AF:

0.000622

AC:

AN:

4824

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10624

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.000118

AC:

AN:

68030

Other (OTH)

AF:

0.00

AC:

AN:

2116

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.507

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.0000708

Hom.:

Bravo

AF:

0.000113

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000233

AC:

ExAC

AF:

0.000132

AC:

Asia WGS

AF:

0.000289

AC:

AN:

3478

EpiCase

AF:

0.000218

EpiControl

AF:

0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1Uncertain:6Benign:2

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:3

Jul 01, 2022

CeGaT Center for Human Genetics Tuebingen

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

MFN2: PM2, PP3 -

Jul 22, 2024

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Previously reported in a pediatric patient with an atypical phenotype including acute neurological failure and deafness; the variant was also identified in his mother who was reported to have a toe-walking gait (PMID: 26686600); Reported previously in the heterozygous state in a patient with CMT; however, further clinical and segregation information was not provided (PMID: 30340945); Reported previously in the homozygous state in a patient with ALS; however, several other homozygous variants were found in other genes as well. Variant was also reported in the heterozygous state in a patient with ALS (no further clinical or segregation information provided), and in the heterozygous state in a control sample (PMID: 31108397); 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: 27582484, 29625556, 31582811, 33415332, 34445196, 30340945, 31108397, 26686600) -

May 31, 2024

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The MFN2 c.1987C>T; p.Arg663Cys variant (rs369762154, ClinVar Variation ID: 214648), is reported heterozygous in the literature in individuals affected with CMT or polyneuropathy and homozygous in an individual with AML (Goldstein 2019, Hoebeke 2018, Di Meglio 2016). This variant is found in the Ashkenazi Jewish population with an allele frequency of 0.19% (20/10370 alleles) in the Genome Aggregation Database (v2.1.1). Computational analyses predict that this variant is deleterious (REVEL: 0.854). However, given the lack of clinical and functional data, the significance of this variant is uncertain at this time. References: Goldstein O et al. Rare homozygosity in amyotrophic lateral sclerosis suggests the contribution of recessive variants to disease genetics. J Neurol Sci. 2019 Jul 15;402:62-68. PMID: 31108397. Hoebeke C et al. Retrospective study of 75 children with peripheral inherited neuropathy: Genotype-phenotype correlations. Arch Pediatr. 2018 Nov;25(8):452-458. PMID: 30340945. Di Meglio C et al. Clinical and allelic heterogeneity in a pediatric cohort of 11 patients carrying MFN2 mutation. Brain Dev. 2016 May;38(5):498-506. PMID: 26686600. -

Charcot-Marie-Tooth disease type 2A2

Pathogenic:1Uncertain:1

Mar 01, 2018

Baylor Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant was determined to be of uncertain significance according to ACMG Guidelines, 2015 [PMID:25741868]. -

Jul 12, 2021

Molecular Medicine for Neurodegenerative and Neuromuscular Diseases Unit, IRCCS Fondazione Stella Maris

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:research

- -

Charcot-Marie-Tooth disease type 2

Benign:2

Jan 12, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Apr 28, 2017

Illumina Laboratory Services, Illumina

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). Publications were found based on this search. The evidence from the literature, in combination with allele frequency data from public databases where available, was sufficient to rule this variant out of causing disease. Therefore, this variant is classified as benign. -

Inborn genetic diseases

Uncertain:1

Jun 02, 2023

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Unlikely to be causative of MFN2-related neuropathy (AD) Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Hereditary motor and sensory neuropathy with optic atrophy

Uncertain:1

Apr 28, 2017

Illumina Laboratory Services, Illumina

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). Publications were found based on this search. However, the evidence from the literature, in combination with allele frequency data from public databases where available, was not sufficient to rule this variant in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.24

BayesDel_addAF

Pathogenic

0.21

BayesDel_noAF

Pathogenic

0.43

CADD

Pathogenic

(source)

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.92

D;D

Eigen

Uncertain

0.55

Eigen_PC

Uncertain

0.49

FATHMM_MKL

Uncertain

0.89

LIST_S2

Pathogenic

0.99

D;.

M_CAP

Pathogenic

0.35

MetaRNN

Uncertain

0.70

D;D

MetaSVM

Pathogenic

1.0

MutationAssessor

Benign

1.9

L;L

PhyloP100

0.78

PrimateAI

Pathogenic

0.85

PROVEAN

Pathogenic

-5.3

D;D

REVEL

Pathogenic

0.85

Sift

Uncertain

0.0010

D;D

Sift4G

Uncertain

0.0080

D;D

Polyphen

1.0

D;D

Vest4

0.89

MVP

0.98

MPC

0.92

ClinPred

0.31

GERP RS

4.5

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.60

gMVP

0.57

Mutation Taster

=55/45

polymorphism

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over