X-101348591-AC-A

Variant names:

• chrX-101348591-AC-A
• rs869320665
• NM_004085.4:c.73delG

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PVS1_Strong PM2 PP5_Moderate

The NM_004085.4(TIMM8A):​c.73delG​(p.Val25fs) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency: Genomes: not found (cov: 22)
• Consequence: TIMM8A NM_004085.4 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 3.15
• Publications: 1 publications found

Genes affected

TIMM8A (HGNC:11817): (translocase of inner mitochondrial membrane 8A) This translocase is involved in the import and insertion of hydrophobic membrane proteins from the cytoplasm into the mitochondrial inner membrane. The gene is mutated in Mohr-Tranebjaerg syndrome/Deafness Dystonia Syndrome (MTS/DDS) and it is postulated that MTS/DDS is a mitochondrial disease caused by a defective mitochondrial protein import system. Defects in this gene also cause Jensen syndrome; an X-linked disease with opticoacoustic nerve atrophy and muscle weakness. This protein, along with TIMM13, forms a 70 kDa heterohexamer. Alternative splicing results in multiple transcript variants encoding distinct isoforms.[provided by RefSeq, Mar 2009]

TIMM8A Gene-Disease associations (from GenCC):

• deafness dystonia syndrome

  Inheritance: XL Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: PanelApp Australia, Ambry Genetics, Orphanet, Labcorp Genetics (formerly Invitae), Genomics England PanelApp, G2P, ClinGen

ACMG classification

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most 50 bp of the penultimate exon, not predicted to undergo nonsense mediated mRNA decay. There are 16 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant X-101348591-AC-A is Pathogenic according to our data. Variant chrX-101348591-AC-A is described in ClinVar as Pathogenic. ClinVar VariationId is 11322.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_004085.4. 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
	TIMM8A	NM_004085.4	MANE Select	c.73delG	p.Val25fs	frameshift	Exon 1 of 2	NP_004076.1
	TIMM8A	NM_001145951.2		c.73delG	p.Val25fs	frameshift	Exon 1 of 2	NP_001139423.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TIMM8A	ENST00000372902.4	TSL:1 MANE Select	c.73delG	p.Val25fs	frameshift	Exon 1 of 2	ENSP00000361993.3
	TIMM8A	ENST00000644112.2		c.73delG	p.Val25fs	frameshift	Exon 1 of 2	ENSP00000494385.1
	TIMM8A	ENST00000645279.1		n.73delG		non_coding_transcript_exon	Exon 1 of 3	ENSP00000494239.1

Frequencies

GnomAD3 genomes Cov.: 22

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 22

ClinVar

ClinVar submissions as Germline

Significance: Pathogenic

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
1	-	-	Deafness dystonia syndrome (1)
1	-	-	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		3.2
Mutation Taster		=2/198	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs869320665; hg19: chrX-100603579;