rs777604559

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_002437.5(MPV17):​c.135delA​(p.Glu45AspfsTer8) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000164 in 1,461,880 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. E45E) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.000016 ( 0 hom. )

Consequence

MPV17
NM_002437.5 frameshift

Scores

Not classified

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:5

Conservation

PhyloP100: 0.307

Publications

3 publications found
Variant links:
Genes affected
MPV17 (HGNC:7224): (mitochondrial inner membrane protein MPV17) This gene encodes a mitochondrial inner membrane protein that is implicated in the metabolism of reactive oxygen species. Mutations in this gene have been associated with the hepatocerebral form of mitochondrial DNA depletion syndrome (MDDS). [provided by RefSeq, Jul 2008]
MPV17 Gene-Disease associations (from GenCC):
  • mitochondrial disease
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • mitochondrial DNA depletion syndrome 6 (hepatocerebral type)
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, G2P, Labcorp Genetics (formerly Invitae), Ambry Genetics
  • Charcot-Marie-Tooth disease, axonal, type 2EE
    Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 18 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 2-27313044-GT-G is Pathogenic according to our data. Variant chr2-27313044-GT-G is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 214662.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MPV17NM_002437.5 linkc.135delA p.Glu45AspfsTer8 frameshift_variant Exon 3 of 8 ENST00000380044.6 NP_002428.1 P39210A0A0S2Z3Z9
MPV17XM_005264326.5 linkc.135delA p.Glu45AspfsTer8 frameshift_variant Exon 3 of 8 XP_005264383.1 P39210A0A0S2Z3Z9
MPV17XM_017004151.2 linkc.87delA p.Glu29AspfsTer8 frameshift_variant Exon 3 of 8 XP_016859640.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MPV17ENST00000380044.6 linkc.135delA p.Glu45AspfsTer8 frameshift_variant Exon 3 of 8 1 NM_002437.5 ENSP00000369383.1 P39210

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD2 exomes
AF:
0.00000795
AC:
2
AN:
251448
AF XY:
0.00000736
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:
0.0000176
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000164
AC:
24
AN:
1461880
Hom.:
0
Cov.:
31
AF XY:
0.0000124
AC XY:
9
AN XY:
727240
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33476
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86254
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53418
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5764
European-Non Finnish (NFE)
AF:
0.0000216
AC:
24
AN:
1112012
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.483
Heterozygous variant carriers
0
2
4
5
7
9
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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
Cov.:
32
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000378
EpiCase
AF:
0.00
EpiControl
AF:
0.000119

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:5
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:2
Jun 03, 2014
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

c.135delA: p.Glu45AspfsX8 (E45DfsX8) in exon 3 of the MPV17 gene (NM_002437.4). The normal sequence with the base that is deleted in braces is: AGGA{A}CACC. The c.135delA mutation in the MPV17 gene has been reported previously in association with mitochondrial DNA depletion syndrome (Uusimaa et al., 2014). The deletion causes a frameshift starting with codon Glutamic Acid 45, changes this amino acid to an Aspartic Acid residue and creates a premature Stop codon at position 8 of the new reading frame, denoted p.Glu45AspfsX8. This mutation is predicted to cause loss of normal protein function either through protein truncation or nonsense-mediated mRNA decay. The variant is found in MITONUC-MITOP panel(s). -

Jan 24, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change creates a premature translational stop signal (p.Glu45Aspfs*8) in the MPV17 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in MPV17 are known to be pathogenic (PMID: 23714749). This variant is present in population databases (rs777604559, gnomAD 0.002%). This premature translational stop signal has been observed in individual(s) with mitochondrial DNA depletion syndrome (PMID: 23714749). ClinVar contains an entry for this variant (Variation ID: 214662). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

Mitochondrial DNA depletion syndrome 6 (hepatocerebral type);C5193076:Charcot-Marie-Tooth disease, axonal, type 2EE Pathogenic:1
Jan 30, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Mitochondrial DNA depletion syndrome 6 (hepatocerebral type) Pathogenic:1
May 26, 2017
Mayo Clinic Laboratories, Mayo Clinic
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Charcot-Marie-Tooth disease, axonal, type 2EE Pathogenic:1
Dec 22, 2023
Baylor Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
PhyloP100
0.31
Mutation Taster
=0/200
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.14
Details are displayed if max score is > 0.2

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

Publications

Other links and lift over

dbSNP: rs777604559; hg19: chr2-27535911; API