1-11992558-C-T

Variant names:

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 5P and 1B. PM1PM2PP2BP6

The NM_014874.4(MFN2):c.179C>T(p.Thr60Met) variant causes a missense change. The variant allele was found at a frequency of 0.0000601 in 1,614,150 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. T60T) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000059 ( 0 hom., cov: 31)

Exomes 𝑓: 0.000060 ( 0 hom. )

Consequence

MFN2
NM_014874.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:4B:2

Conservation

PhyloP100: 5.58

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 Uncertain_significance. Variant got 4 ACMG points.

PM1

In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 7 uncertain in NM_014874.4

PM2

Very rare variant in population databases, with high coverage;

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.

BP6

Variant 1-11992558-C-T is Benign according to our data. Variant chr1-11992558-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 246508.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Benign=1, Uncertain_significance=3}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MFN2	NM_014874.4 link	c.179C>T	p.Thr60Met	missense_variant	Exon 4 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.179C>T	p.Thr60Met	missense_variant	Exon 4 of 19	1	NM_014874.4	ENSP00000235329.5		O95140-1

Frequencies

GnomAD3 genomes

AF:

0.0000591

AC:

AN:

152160

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000483

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000654

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000385

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000588

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000477

AC:

AN:

251490

Hom.:

AF XY:

0.0000515

AC XY:

AN XY:

135918

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000109

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000791

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.0000602

AC:

AN:

1461872

Hom.:

Cov.:

AF XY:

0.0000715

AC XY:

AN XY:

727242

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

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:

0.0000749

Gnomad4 NFE exome

AF:

0.0000710

Gnomad4 OTH exome

AF:

0.0000497

GnomAD4 genome

AF:

0.0000591

AC:

AN:

152278

Hom.:

Cov.:

AF XY:

0.0000537

AC XY:

AN XY:

74444

show subpopulations

Gnomad4 AFR

AF:

0.0000481

Gnomad4 AMR

AF:

0.0000654

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000386

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000588

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000113

Hom.:

Bravo

AF:

0.0000378

ESP6500AA

AF:

0.000227

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.0000576

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:4Benign:2

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Charcot-Marie-Tooth disease type 2

Uncertain:1Benign:1

Aug 14, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces threonine, which is neutral and polar, with methionine, which is neutral and non-polar, at codon 60 of the MFN2 protein (p.Thr60Met). This variant is present in population databases (rs138345244, gnomAD 0.01%). This missense change has been observed in individual(s) with clinical features of autosomal dominant MFN2-related conditions (Invitae). ClinVar contains an entry for this variant (Variation ID: 246508). 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) indicates that this missense variant is expected to disrupt MFN2 protein function with a positive predictive value of 80%. 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. -

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

Inborn genetic diseases

Uncertain:1

Apr 07, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.179C>T (p.T60M) alteration is located in exon 4 (coding exon 2) of the MFN2 gene. This alteration results from a C to T substitution at nucleotide position 179, causing the threonine (T) at amino acid position 60 to be replaced by a methionine (M). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Optic atrophy

Uncertain:1

Jan 01, 2023

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

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

not provided

Uncertain:1

Mar 28, 2016

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The T60M variant has notbeen published as a pathogenic variant, nor has it been reported as a benign variant to our knowledge.The T60M variant was not observed with any significant frequency in approximately 6,500individuals of European and African American ancestry in the NHLBI Exome Sequencing Project butthe 1000 Genomes Project reports T60M was observed in 2/1008 (0.02%) alleles from individuals ofEast Asian background. This substitution occurs at a position that is conserved across species. TheT60M variant is a non-conservative amino acid substitution, which is likely to impact secondaryprotein structure as these residues differ in polarity, charge, size and/or other properties. However, insilico analysis is inconsistent in its predictions as to whether or not the variant is damaging to theprotein structure/function. Therefore, based on the currently available information, it is unclearwhether this variant is a pathogenic variant or a rare benign variant. -

Hereditary motor and sensory neuropathy with optic atrophy

Benign:1

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.16

BayesDel_addAF

Pathogenic

0.21

BayesDel_noAF

Pathogenic

0.30

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Benign

0.27

T;T;.

Eigen

Uncertain

0.65

Eigen_PC

Uncertain

0.66

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Uncertain

0.97

D;.;D

M_CAP

Pathogenic

0.32

MetaRNN

Uncertain

0.49

T;T;T

MetaSVM

Pathogenic

1.1

MutationAssessor

Uncertain

2.3

M;M;.

PrimateAI

Uncertain

0.53

PROVEAN

Benign

-1.2

N;N;N

REVEL

Pathogenic

0.71

Sift

Benign

0.11

T;T;D

Sift4G

Benign

0.21

T;T;D

Polyphen

0.98

D;D;.

Vest4

0.50

MVP

0.90

MPC

1.5

ClinPred

0.26

GERP RS

5.5

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Varity_R

0.29

gMVP

0.57

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