1-12007168-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM2PP2PP3_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

13
4
2

Clinical Significance

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

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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 5 ACMG points.

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, 0.917

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MFN2NM_014874.4 linkc.1988G>T p.Arg663Leu 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
MFN2ENST00000235329.10 linkc.1988G>T p.Arg663Leu missense_variant Exon 17 of 19 1 NM_014874.4 ENSP00000235329.5 O95140-1

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152216
Hom.:
0
Cov.:
33
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
GnomAD3 exomes
AF:
0.0000119
AC:
3
AN:
251402
Hom.:
0
AF XY:
0.0000147
AC XY:
2
AN XY:
135902
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:
0.0000264
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000417
AC:
61
AN:
1461824
Hom.:
0
Cov.:
33
AF XY:
0.0000358
AC XY:
26
AN XY:
727224
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:
0.0000540
Gnomad4 OTH exome
AF:
0.0000166
GnomAD4 genome
AF:
0.0000197
AC:
3
AN:
152216
Hom.:
0
Cov.:
33
AF XY:
0.0000134
AC XY:
1
AN XY:
74368
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:
0.0000441
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000614
Hom.:
0
Bravo
AF:
0.0000189
ExAC
AF:
0.00000824
AC:
1
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
D
BayesDel_noAF
Pathogenic
0.47
CADD
Pathogenic
29
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.92
D;D
Eigen
Pathogenic
0.73
Eigen_PC
Pathogenic
0.69
FATHMM_MKL
Pathogenic
0.97
D
LIST_S2
Pathogenic
0.99
D;.
M_CAP
Pathogenic
0.43
D
MetaRNN
Pathogenic
0.92
D;D
MetaSVM
Pathogenic
1.0
D
MutationAssessor
Benign
1.9
L;L
PrimateAI
Pathogenic
0.82
D
PROVEAN
Pathogenic
-4.6
D;D
REVEL
Pathogenic
0.94
Sift
Uncertain
0.0060
D;D
Sift4G
Uncertain
0.047
D;D
Polyphen
0.98
D;D
Vest4
0.87
MutPred
0.51
Loss of MoRF binding (P = 0.0098);Loss of MoRF binding (P = 0.0098);
MVP
0.98
MPC
0.87
ClinPred
0.99
D
GERP RS
4.6
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.60
gMVP
0.67

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: rs766735605; hg19: chr1-12067225; COSMIC: COSV99336410; API