NM_016589.4:c.194+2T>C

Variant names:

• chr3-119498929-T-C
• NM_016589.4:c.194+2T>C

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PVS1_Strong PM2 PP5_Moderate

The NM_016589.4(TIMMDC1):​c.194+2T>C variant causes a splice donor, intron change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 2/2 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: TIMMDC1 NM_016589.4 splice_donor, intron
• Scores: Splicing: ADA: 0.9996
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 4.36

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]

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.44405594 fraction of the gene. Cryptic splice site detected, with MaxEntScore 3.9, offset of 27, new splice context is: gggGTaggg. Cryptic site results in inframe 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 3-119498929-T-C is Pathogenic according to our data. Variant chr3-119498929-T-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 2501222.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TIMMDC1	NM_016589.4	c.194+2T>C		splice_donor_variant, intron_variant	Intron 1 of 6	ENST00000494664.6	NP_057673.2
TIMMDC1	XM_017006556.2	c.194+2T>C		splice_donor_variant, intron_variant	Intron 1 of 2		XP_016862045.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TIMMDC1	ENST00000494664.6	c.194+2T>C		splice_donor_variant, intron_variant	Intron 1 of 6	1	NM_016589.4	ENSP00000418803.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Mitochondrial complex 1 deficiency, nuclear type 31 Pathogenic:1

Mar 28, 2023

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: C3orf1 (TIMMDC1) c.194+2T>C is located in a canonical splice-site and is predicted to affect mRNA splicing resulting in a significantly altered protein due to either exon skipping, shortening, or inclusion of intronic material. The variant was absent in 250236 control chromosomes. To our knowledge, no occurrence of c.194+2T>C in individuals affected with Mitochondrial Complex 1 Deficiency, Nuclear Type 31 and no experimental evidence demonstrating its impact on protein function have been reported. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014. Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.32	D
BayesDel_noAF	Pathogenic	0.22
CADD	Pathogenic	30
DANN	Uncertain	0.99
Eigen	Pathogenic	0.99
Eigen_PC	Pathogenic	0.82
FATHMM_MKL	Benign	0.74	D
GERP RS		5.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
SpliceAI score (max)		0.74		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.36		Position offset: 13
DS_DL_spliceai		0.74		Position offset: -2

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr3-119217776;