8-73976283-T-C

Position:

• chr8-73976283-T-C

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_017866.6(TMEM70):​c.2T>C​(p.Met1?) variant causes a start lost change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: TMEM70 NM_017866.6 start_lost
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 1.52

Genes affected

TMEM70 (HGNC:26050): (transmembrane protein 70) This gene likely encodes a mitochondrial membrane protein. The encoded protein may play a role in biogenesis of mitochondrial ATP synthase. Mutations in this gene have been associated with neonatal mitochondrial encephalocardiomyopathy due to ATP synthase deficiency. Alternatively spliced transcript variants have been described. [provided by RefSeq, Feb 2010]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PVS1: Start lost variant, no new inframe start found.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 8-73976283-T-C is Pathogenic according to our data. Variant chr8-73976283-T-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 936698.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TMEM70	NM_017866.6	c.2T>C	p.Met1?	start_lost	1/3	ENST00000312184.6
TMEM70	NM_001040613.3	c.2T>C	p.Met1?	start_lost	1/3
TMEM70	NR_033334.2	n.89T>C		non_coding_transcript_exon_variant	1/4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TMEM70	ENST00000312184.6	c.2T>C	p.Met1?	start_lost	1/3	1	NM_017866.6	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Mitochondrial complex V (ATP synthase) deficiency nuclear type 2 Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 22, 2019

In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. This variant disrupts the initiator methionine in TMEM70. If translation initiates from the next in-frame methionine, the TMEM70 protein would no longer include the region containing the p.Thr97 amino acid residue. Other variant(s) that disrupt this residue have been observed in individuals with TMEM70-related conditions (PMID: 30724636), which suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. This variant has been observed in individual(s) with clinical features of mitochondrial complex V deficiency (Invitae). In at least one individual the data is consistent with the variant being in trans (on the opposite chromosome) from a pathogenic variant. This variant is not present in population databases (ExAC no frequency). This sequence change affects the initiator methionine of the TMEM70 mRNA. The next in-frame methionine is located at codon 100. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Benign	-0.14
CADD	Benign	20
DANN	Benign	0.92
DEOGEN2	Benign	0.0011	.;T
Eigen	Benign	0.18
Eigen_PC	Benign	0.11
FATHMM_MKL	Uncertain	0.88	D
LIST_S2	Uncertain	0.90	D;D
M_CAP	Pathogenic	0.90	D
MetaRNN	Pathogenic	0.98	D;D
MetaSVM	Benign	-0.63	T
MutationTaster	Benign	1.0	D;D
PROVEAN	Uncertain	-2.9	D;N
REVEL	Benign	0.29
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		0.90	.;P
Vest4		0.72
MutPred		0.84		Gain of catalytic residue at M1 (P = 0.0186);Gain of catalytic residue at M1 (P = 0.0186);
MVP		0.55
ClinPred		0.99	D
GERP RS		4.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.96
gMVP		0.62

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

Other links and lift over

dbSNP: rs1815641175; hg19: chr8-74888518;