8-124539250-C-T

Variant names:

• chr8-124539250-C-T
• rs759625380
• NM_005005.3:c.64C>T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP3

The NM_005005.3(NDUFB9):​c.64C>T​(p.Arg22Trp) variant causes a missense change. The variant allele was found at a frequency of 0.0000041 in 1,461,874 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R22Q) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000041 (0 hom.)
• Consequence: NDUFB9 NM_005005.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 4.05

Genes affected

NDUFB9 (HGNC:7704): (NADH:ubiquinone oxidoreductase subunit B9) The protein encoded by this gene is a subunit of the mitochondrial oxidative phosphorylation complex I (nicotinamide adenine dinucleotide: ubiquinone oxidoreductase). Complex I is localized to the inner mitochondrial membrane and functions to dehydrogenate nicotinamide adenine dinucleotide and to shuttle electrons to coenzyme Q. Complex I deficiency is the most common defect found in oxidative phosphorylation disorders and results in a range of conditions, including lethal neonatal disease, hypertrophic cardiomyopathy, liver disease, and adult-onset neurodegenerative disorders. Pseudogenes of this gene are found on chromosomes five, seven and eight. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jul 2015]

TATDN1 (HGNC:24220): (TatD DNase domain containing 1) Predicted to enable 3'-5'-exodeoxyribonuclease activity. Predicted to be involved in DNA metabolic process and nucleic acid phosphodiester bond hydrolysis. Located in nucleoplasm. [provided by Alliance of Genome Resources, Apr 2022]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.76

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NDUFB9	NM_005005.3	c.64C>T	p.Arg22Trp	missense_variant	Exon 1 of 4	ENST00000276689.8	NP_004996.1
TATDN1	NM_032026.4	c.-204G>A		upstream_gene_variant		ENST00000276692.11	NP_114415.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NDUFB9	ENST00000276689.8	c.64C>T	p.Arg22Trp	missense_variant	Exon 1 of 4	1	NM_005005.3	ENSP00000276689.3
TATDN1	ENST00000276692.11	c.-204G>A		upstream_gene_variant		1	NM_032026.4	ENSP00000276692.6

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000797 AC: 2 AN: 251016 Hom.: 0 AF XY: 0.0000147 AC XY: 2 AN XY: 135822

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000176

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000410 AC: 6 AN: 1461874 Hom.: 0 Cov.: 33 AF XY: 0.00000825 AC XY: 6 AN XY: 727236

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000450

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ExAC AF: 0.0000165 AC: 2

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Uncertain:1

Sep 10, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.64C>T (p.R22W) alteration is located in exon 1 (coding exon 1) of the NDUFB9 gene. This alteration results from a C to T substitution at nucleotide position 64, causing the arginine (R) at amino acid position 22 to be replaced by a tryptophan (W). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

not provided Uncertain:1

Jul 16, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 22 of the NDUFB9 protein (p.Arg22Trp). This variant is present in population databases (rs759625380, gnomAD 0.0009%). This variant has not been reported in the literature in individuals affected with NDUFB9-related conditions. An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.62
BayesDel_addAF	Uncertain	0.10	D
BayesDel_noAF	Benign	-0.090
CADD	Pathogenic	34
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.54	.;D;.;T
Eigen	Uncertain	0.35
Eigen_PC	Uncertain	0.26
FATHMM_MKL	Benign	0.73	D
LIST_S2	Pathogenic	0.99	D;D;D;D
M_CAP	Pathogenic	0.60	D
MetaRNN	Pathogenic	0.76	D;D;D;D
MetaSVM	Uncertain	0.12	D
MutationAssessor	Pathogenic	3.1	.;M;.;.
PrimateAI	Uncertain	0.70	T
PROVEAN	Uncertain	-4.4	.;D;D;D
REVEL	Uncertain	0.60
Sift	Uncertain	0.0010	.;D;D;D
Sift4G	Uncertain	0.0030	.;D;D;D
Polyphen		1.0	.;D;.;.
Vest4		0.49, 0.49, 0.54
MutPred		0.62		Loss of methylation at K21 (P = 0.0558);Loss of methylation at K21 (P = 0.0558);Loss of methylation at K21 (P = 0.0558);Loss of methylation at K21 (P = 0.0558);
MVP		0.96
MPC		0.29
ClinPred		1.0	D
GERP RS		4.5
RBP_binding_hub_radar		1.1
RBP_regulation_power_radar		2.8
Varity_R		0.63
gMVP		0.71

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs759625380; hg19: chr8-125551491;