chr1-12002025-AC-GA

Variant names:

• chr1-12002025-AC-GA
• NM_014874.4:c.1082_1083delACinsGA
• MFN2 p.His361Arg

Variant summary

Our verdict is Pathogenic. The variant received 14 ACMG points: 14P and 0B. PS1_Very_Strong PM1 PM5 PP2 PP3

The NM_014874.4(MFN2):​c.1082_1083delACinsGA​(p.His361Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. It is difficult to determine the true allele frequency of this variant because it is of type MNV, and the frequency of such variant types in population databases may be underestimated and unreliable. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another nucleotide change resulting in the same amino acid substitution has been previously reported as Likely pathogenic in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. H361Q) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: MFN2 NM_014874.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 8.95
• Publications: 0 publications found

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: G2P, Labcorp Genetics (formerly Invitae)
• multiple symmetric lipomatosis with partial lipodystrophy

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• 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

ACMG classification

Our verdict: Pathogenic. The variant received 14 ACMG points.

• PS1: Transcript NM_014874.4 (MFN2) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in ClinVar.
• PM1: In a hotspot region, there are 13 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 9 uncertain in NM_014874.4
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr1-12002026-C-G is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 864426.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• 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, axonal, autosomal recessive, type 2a2b;, multiple symmetric lipomatosis, Charcot-Marie-Tooth disease type 2A2, axonal hereditary motor and sensory neuropathy, neuropathy, hereditary motor and sensory, type 6A, multiple symmetric lipomatosis with partial lipodystrophy, severe early-onset axonal neuropathy due to MFN2 deficiency, hereditary motor and sensory neuropathy type 6.
• PP3: No computational evidence supports a deleterious effect, but strongly conserved according to phyloP

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_014874.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MFN2	NM_014874.4	MANE Select	c.1082_1083delACinsGA	p.His361Arg	missense	N/A	NP_055689.1	O95140-1
	MFN2	NM_001127660.2		c.1082_1083delACinsGA	p.His361Arg	missense	N/A	NP_001121132.1	O95140-1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MFN2	ENST00000235329.10	TSL:1 MANE Select	c.1082_1083delACinsGA	p.His361Arg	missense	N/A	ENSP00000235329.5	O95140-1
	MFN2	ENST00000675298.1		c.1082_1083delACinsGA	p.His361Arg	missense	N/A	ENSP00000501839.1	A0A6Q8PFJ4
	MFN2	ENST00000675817.1		c.1082_1083delACinsGA	p.His361Arg	missense	N/A	ENSP00000502422.1	A0A6Q8PGV8

Frequencies

GnomAD3 genomes Cov.: 33

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		8.9

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

hg19: chr1-12062082;