2-27312247-C-T

Variant names:

• chr2-27312247-C-T
• rs1423840146
• NM_002437.5:c.376-1G>A

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PVS1_Moderate PM2 PP5_Moderate

The NM_002437.5(MPV17):​c.376-1G>A variant causes a splice acceptor, intron change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: MPV17 NM_002437.5 splice_acceptor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 5.60
• Publications: 2 publications found

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)

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.06214689 fraction of the gene. Cryptic splice site detected, with MaxEntScore 7.9, offset of 1, new splice context is: tccttctctgtctccccaAGatt. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 2-27312247-C-T is Pathogenic according to our data. Variant chr2-27312247-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 522376.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_002437.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MPV17	NM_002437.5	MANE Select	c.376-1G>A		splice_acceptor intron	N/A	NP_002428.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MPV17	ENST00000380044.6	TSL:1 MANE Select	c.376-1G>A		splice_acceptor intron	N/A	ENSP00000369383.1
	MPV17	ENST00000233545.6	TSL:1	c.376-1G>A		splice_acceptor intron	N/A	ENSP00000233545.2
	MPV17	ENST00000403262.6	TSL:1	c.376-1G>A		splice_acceptor intron	N/A	ENSP00000385671.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Mitochondrial DNA depletion syndrome 6 (hepatocerebral type) Pathogenic:1

Dec 01, 2017

Wong Mito Lab, Molecular and Human Genetics, Baylor College of Medicine

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.62	D
BayesDel_noAF	Pathogenic	0.24
CADD	Pathogenic	33
DANN	Uncertain	0.99
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.86
FATHMM_MKL	Uncertain	0.94	D
PhyloP100		5.6
GERP RS		5.0
Mutation Taster		=0/100	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		0.96		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.37		Position offset: -2
DS_AL_spliceai		0.96		Position offset: -1

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

Other links and lift over

dbSNP: rs1423840146; hg19: chr2-27535115;