X-101346595-G-A

Variant names:

• chrX-101346595-G-A
• rs80356560
• NM_004085.4:c.198C>T

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 2P and 3B. PM2 BP4_Moderate BP7

The NM_004085.4(TIMM8A):​c.198C>T​(p.Cys66Cys) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000273 in 1,098,111 control chromosomes in the GnomAD database, with no homozygous occurrence. There are no hemizygote samples in GnomAD. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 23)
  • Exomes 𝑓: 0.0000027 (0 hom. 0 hem.)
• Consequence: TIMM8A NM_004085.4 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.318
• Publications: 0 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_benign. The variant received -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.46).
• BP7: Synonymous conserved (PhyloP=0.318 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TIMM8A	NM_004085.4	c.198C>T	p.Cys66Cys	synonymous_variant	Exon 2 of 2	ENST00000372902.4	NP_004076.1
TIMM8A	NM_001145951.2	c.*1792C>T		3_prime_UTR_variant	Exon 2 of 2		NP_001139423.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TIMM8A	ENST00000372902.4	c.198C>T	p.Cys66Cys	synonymous_variant	Exon 2 of 2	1	NM_004085.4	ENSP00000361993.3

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome AF: 0.00000273 AC: 3 AN: 1098111 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 363467

African (AFR) AF: 0.0000379 AC: 1 AN: 26399

American (AMR) AF: 0.00 AC: 0 AN: 35207

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 19386

East Asian (EAS) AF: 0.00 AC: 0 AN: 30204

South Asian (SAS) AF: 0.00 AC: 0 AN: 54143

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 40532

Middle Eastern (MID) AF: 0.000243 AC: 1 AN: 4119

European-Non Finnish (NFE) AF: 0.00000119 AC: 1 AN: 842030

Other (OTH) AF: 0.00 AC: 0 AN: 46091

GnomAD4 genome Cov.: 23

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.46
CADD	Benign	6.2
DANN	Benign	0.84
PhyloP100		0.32

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: rs80356560; hg19: chrX-100601583; COSMIC: COSV58117217; COSMIC: COSV58117217;