1-12007168-G-T

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PP2PP3_Moderate

The NM_014874.4(MFN2):c.1988G>T(p.Arg663Leu) variant causes a missense change. The variant allele was found at a frequency of 0.0000397 in 1,614,040 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R663C) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000042 ( 0 hom. )

Consequence

MFN2
NM_014874.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:5

Conservation

PhyloP100: 5.58

Publications

5 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 3 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.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.917

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MFN2	NM_014874.4 link	c.1988G>T	p.Arg663Leu	missense_variant	Exon 17 of 19	ENST00000235329.10	NP_055689.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MFN2	ENST00000235329.10 link	c.1988G>T	p.Arg663Leu	missense_variant	Exon 17 of 19	1	NM_014874.4	ENSP00000235329.5

Frequencies

GnomAD3 genomes

AF:

0.0000197

AC:

AN:

152216

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000441

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000119

AC:

AN:

251402

AF XY:

0.0000147

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 FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000264

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000417

AC:

AN:

1461824

Hom.:

Cov.:

AF XY:

0.0000358

AC XY:

AN XY:

727224

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53354

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.0000540

AC:

AN:

1112008

Other (OTH)

AF:

0.0000166

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.467

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:

0.0000197

AC:

AN:

152216

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74368

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41462

American (AMR)

AF:

0.00

AC:

AN:

15286

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5196

South Asian (SAS)

AF:

0.00

AC:

AN:

4836

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10626

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000441

AC:

AN:

68022

Other (OTH)

AF:

0.00

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.542

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:

0.0000614

Hom.:

Bravo

AF:

0.0000189

ExAC

AF:

0.00000824

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Charcot-Marie-Tooth disease

Uncertain:1

Molecular Genetics Laboratory, London Health Sciences Centre

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

not specified

Uncertain:1

Oct 28, 2016

Athena Diagnostics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Inborn genetic diseases

Uncertain:1

Dec 15, 2022

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The c.1988G>T (p.R663L) alteration is located in exon 17 (coding exon 15) of the MFN2 gene. This alteration results from a G to T substitution at nucleotide position 1988, causing the arginine (R) at amino acid position 663 to be replaced by a leucine (L). Based on data from the Genome Aggregation Database (gnomAD), the MFN2 c.1988G>T alteration was observed in 0.001% (4/282,798) total alleles studied. This amino acid position is conserved in available vertebrate species, except for lizard. The alteration is predicted deleterious by in silico models:_x000D_ _x000D_ The p.R663L alteration is predicted to be possibly damaging by Polyphen and deleterious by SIFT in silico analyses. Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear.

Charcot-Marie-Tooth disease type 2

Uncertain:1

Oct 24, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with leucine, which is neutral and non-polar, at codon 663 of the MFN2 protein (p.Arg663Leu). This variant is present in population databases (rs766735605, gnomAD 0.003%). This variant has not been reported in the literature in individuals affected with MFN2-related conditions. ClinVar contains an entry for this variant (Variation ID: 447720). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt MFN2 protein function with a positive predictive value of 95%. 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 provided

Uncertain:1

Mar 27, 2017

Mayo Clinic Laboratories, Mayo Clinic

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.38

BayesDel_addAF

Pathogenic

0.45

BayesDel_noAF

Pathogenic

0.47

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.92

D;D

Eigen

Pathogenic

0.73

Eigen_PC

Pathogenic

0.69

FATHMM_MKL

Pathogenic

0.97

LIST_S2

Pathogenic

0.99

D;.

M_CAP

Pathogenic

0.43

MetaRNN

Pathogenic

0.92

D;D

MetaSVM

Pathogenic

1.0

MutationAssessor

Benign

1.9

L;L

PhyloP100

5.6

PrimateAI

Pathogenic

0.82

PROVEAN

Pathogenic

-4.6

D;D

REVEL

Pathogenic

0.94

Sift

Uncertain

0.0060

D;D

Sift4G

Uncertain

0.047

D;D

Vest4

0.87

ClinPred

0.99

GERP RS

4.6

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.60

gMVP

0.67

Mutation Taster

=37/63

disease causing

(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