rs28940293

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PM1PM2PP2PP3PP5_Very_Strong

The NM_014874.4(MFN2):​c.227T>C​(p.Leu76Pro) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,614,100 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 Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L76R) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 31)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

MFN2
NM_014874.4 missense

Scores

6
6
7

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:6

Conservation

PhyloP100: 1.89
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 14 ACMG points.

PM1
In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 8 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.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.791
PP5
Variant 1-11992606-T-C is Pathogenic according to our data. Variant chr1-11992606-T-C is described in ClinVar as [Pathogenic]. Clinvar id is 2270.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr1-11992606-T-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MFN2NM_014874.4 linkc.227T>C p.Leu76Pro 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
MFN2ENST00000235329.10 linkc.227T>C p.Leu76Pro missense_variant Exon 4 of 19 1 NM_014874.4 ENSP00000235329.5 O95140-1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152206
Hom.:
0
Cov.:
31
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461894
Hom.:
0
Cov.:
31
AF XY:
0.00000138
AC XY:
1
AN XY:
727248
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:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
8.99e-7
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152206
Hom.:
0
Cov.:
31
AF XY:
0.00
AC XY:
0
AN XY:
74358
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000147
Gnomad4 OTH
AF:
0.00
Bravo
AF:
0.00000378

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:6
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:4
Aug 28, 2017
Eurofins Ntd Llc (ga)
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

May 21, 2019
Mayo Clinic Laboratories, Mayo Clinic
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

PS3, PS4, PM2, PP1 -

Jul 29, 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 (http://gnomad.broadinstitute.org). This variant has been identified in at least one individual with clinical features of Charcot-Marie-Tooth disease. This variant occurs as the most likely explanation for disease in a significant number of internal cases, suggesting this variant is associated with disease. Assessment of experimental evidence suggests this variant results in abnormal protein function. Studies demonstrate significant changes to mitochondrial function in various model systems (PMID: 20335458, 26968460, 29898954). The variant is located in a region that is considered important for protein function and/or structure. -

Dec 02, 2024
GeneDx
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Reported as a common pathogenic variant in individuals with Charcot-Marie-Tooth (PMID: 25614874, 19584314); Segregates with disease in affected individuals in a family with CMT2A characterized by severe distal weakness and atrophy with mild distal sensory loss, proximal muscle strength was reported as normal and the age of onset ranged from 7 to 44 years (PMID: 15064763, 10732809); Reported previously as a pathogenic variant in a patient with neuropathy; however, no other clinical information was provided (PMID: 31701603); Functional studies suggest the L76P variant results in mitochondrial aggregation and altered mitochondrial mobility and morphology (PMID: 17215403, 26968460, 29898954); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 17296794, 26143526, 10732809, 33049996, 26968460, 20335458, 19584314, 22957060, 16714318, 29898954, 31127728, 9333264, 28380071, 31096646, Yenkin2022[FunctionalStudy], 15064763, 17215403, 25614874, 31701603, 36098092) -

Charcot-Marie-Tooth disease type 2A2 Pathogenic:1
May 01, 2004
OMIM
Significance: Pathogenic
Review Status: no assertion criteria provided
Collection Method: literature only

- -

Charcot-Marie-Tooth disease type 2 Pathogenic:1
Dec 25, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change replaces leucine, which is neutral and non-polar, with proline, which is neutral and non-polar, at codon 76 of the MFN2 protein (p.Leu76Pro). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with Charcot-Marie-Tooth disease (PMID: 10732809, 15064763, 16714318, 25614874). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 2270). 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, 20335458). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.51
BayesDel_addAF
Pathogenic
0.42
D
BayesDel_noAF
Pathogenic
0.36
CADD
Benign
23
DANN
Uncertain
0.99
DEOGEN2
Uncertain
0.52
D;D;.
Eigen
Benign
0.18
Eigen_PC
Uncertain
0.27
FATHMM_MKL
Uncertain
0.89
D
LIST_S2
Benign
0.84
T;.;T
M_CAP
Pathogenic
0.42
D
MetaRNN
Pathogenic
0.79
D;D;D
MetaSVM
Pathogenic
1.0
D
MutationAssessor
Benign
1.9
L;L;.
PrimateAI
Uncertain
0.59
T
PROVEAN
Benign
-1.7
N;N;D
REVEL
Pathogenic
0.72
Sift
Benign
0.26
T;T;T
Sift4G
Benign
0.28
T;T;T
Polyphen
0.74
P;P;.
Vest4
0.75
MutPred
0.73
Gain of disorder (P = 0.0109);Gain of disorder (P = 0.0109);Gain of disorder (P = 0.0109);
MVP
0.98
MPC
1.2
ClinPred
0.66
D
GERP RS
5.4
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.84
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.

Other links and lift over

dbSNP: rs28940293; hg19: chr1-12052663; API