5-140641692-C-G

Variant names:

• chr5-140641692-C-G
• rs201866963
• NM_018502.5:c.226C>G

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM2 BP4

The NM_018502.5(TMCO6):​c.226C>G​(p.Arg76Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,790 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/22 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R76W) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: TMCO6 NM_018502.5 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 1.71
• Publications: 0 publications found

Genes affected

TMCO6 (HGNC:28814): (transmembrane and coiled-coil domains 6) Predicted to enable nuclear import signal receptor activity. Predicted to be involved in protein import into nucleus. Predicted to be integral component of membrane. [provided by Alliance of Genome Resources, Apr 2022]

NDUFA2 (HGNC:7685): (NADH:ubiquinone oxidoreductase subunit A2) The encoded protein is a subunit of the hydrophobic protein fraction of the NADH:ubiquinone oxidoreductase (complex 1), the first enzyme complex in the electron transport chain located in the inner mitochondrial membrane, and may be involved in regulating complex I activity or its assembly via assistance in redox processes. Mutations in this gene are associated with Leigh syndrome, an early-onset progressive neurodegenerative disorder. Alternative splicing results in multiple transcript variants.[provided by RefSeq, May 2010]

NDUFA2 Gene-Disease associations (from GenCC):

• mitochondrial complex I deficiency, nuclear type 13

  Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• Leigh syndrome

  Inheritance: AR Classification: MODERATE Submitted by: ClinGen
• cystic leukoencephalopathy without megalencephaly

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

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.2839283).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TMCO6	NM_018502.5	c.226C>G	p.Arg76Gly	missense_variant	Exon 3 of 12	ENST00000394671.8	NP_060972.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TMCO6	ENST00000394671.8	c.226C>G	p.Arg76Gly	missense_variant	Exon 3 of 12	2	NM_018502.5	ENSP00000378166.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461790 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727202

⚠️ 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: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44718

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26132

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86254

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5710

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111994

Other (OTH) AF: 0.00 AC: 0 AN: 60384

⚠️ 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
AlphaMissense	Benign	0.085
BayesDel_addAF	Benign	-0.11	T
BayesDel_noAF	Benign	-0.39
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Benign	0.038	T;.
Eigen	Benign	-0.29
Eigen_PC	Benign	-0.17
FATHMM_MKL	Uncertain	0.78	D
LIST_S2	Benign	0.82	T;T
M_CAP	Benign	0.019	T
MetaRNN	Benign	0.28	T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	1.7	L;L
PhyloP100		1.7
PrimateAI	Benign	0.33	T
PROVEAN	Benign	-1.9	N;N
REVEL	Benign	0.074
Sift	Benign	0.038	D;D
Sift4G	Uncertain	0.021	D;D
Polyphen		0.13	B;B
Vest4		0.60
MutPred		0.36		Loss of MoRF binding (P = 0.036);Loss of MoRF binding (P = 0.036);
MVP		0.42
MPC		0.58
ClinPred		0.67	D
GERP RS		4.4
Varity_R		0.096
gMVP		0.12
Mutation Taster		=81/19	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs201866963; hg19: chr5-140021277;