3-119503609-G-T

Variant names:

• chr3-119503609-G-T
• rs1131265
• NM_016589.4:c.438G>T

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_016589.4(TIMMDC1):​c.438G>T​(p.Val146Val) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000687 in 1,455,946 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. V146V) has been classified as Benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: TIMMDC1 NM_016589.4 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.599
• Publications: 0 publications found

Genes affected

TIMMDC1 (HGNC:1321): (translocase of inner mitochondrial membrane domain containing 1) Located in mitochondrion and nucleoplasm. Implicated in nuclear type mitochondrial complex I deficiency 31. [provided by Alliance of Genome Resources, Apr 2022]

TIMMDC1 Gene-Disease associations (from GenCC):

• mitochondrial complex I deficiency, nuclear type 31

  Inheritance: AR Classification: STRONG, MODERATE Submitted by: Illumina, Labcorp Genetics (formerly Invitae)
• mitochondrial complex I deficiency

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• Leigh syndrome

  Inheritance: AR Classification: LIMITED Submitted by: ClinGen

ACMG classification

Our verdict: Likely_benign. The variant received -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.47).
• BP7: Synonymous conserved (PhyloP=0.599 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TIMMDC1	NM_016589.4	c.438G>T	p.Val146Val	synonymous_variant	Exon 3 of 7	ENST00000494664.6	NP_057673.2
TIMMDC1	NM_001438040.1	c.194+4682G>T		intron_variant	Intron 1 of 2		NP_001424969.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TIMMDC1	ENST00000494664.6	c.438G>T	p.Val146Val	synonymous_variant	Exon 3 of 7	1	NM_016589.4	ENSP00000418803.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.87e-7 AC: 1 AN: 1455946 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 724054

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33300

American (AMR) AF: 0.00 AC: 0 AN: 43664

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25986

East Asian (EAS) AF: 0.00 AC: 0 AN: 39610

South Asian (SAS) AF: 0.0000118 AC: 1 AN: 85052

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53156

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5738

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1109342

Other (OTH) AF: 0.00 AC: 0 AN: 60098

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.47
CADD	Benign	7.8
DANN	Benign	0.57
PhyloP100		0.60

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.080		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: rs1131265; hg19: chr3-119222456;