NM_000126.4:c.495_496delGT

Variant names:

• chr15-76286436-AAC-A
• rs1298299792
• NM_000126.4:c.495_496delGT

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000126.4(ETFA):​c.495_496delGT​(p.Ser167CysfsTer7) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000116 in 1,461,466 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.000012 (0 hom.)
• Consequence: ETFA NM_000126.4 frameshift
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: 8.83

Genes affected

ETFA (HGNC:3481): (electron transfer flavoprotein subunit alpha) ETFA participates in catalyzing the initial step of the mitochondrial fatty acid beta-oxidation. It shuttles electrons between primary flavoprotein dehydrogenases and the membrane-bound electron transfer flavoprotein ubiquinone oxidoreductase. Defects in electron-transfer-flavoprotein have been implicated in type II glutaricaciduria in which multiple acyl-CoA dehydrogenase deficiencies result in large excretion of glutaric, lactic, ethylmalonic, butyric, isobutyric, 2-methyl-butyric, and isovaleric acids. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 15-76286436-AAC-A is Pathogenic according to our data. Variant chr15-76286436-AAC-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 459956.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ETFA	NM_000126.4	c.495_496delGT	p.Ser167CysfsTer7	frameshift_variant	Exon 6 of 12	ENST00000557943.6	NP_000117.1
ETFA	NM_001127716.2	c.348_349delGT	p.Ser118CysfsTer7	frameshift_variant	Exon 5 of 11		NP_001121188.1
ETFA	XR_007064434.1	n.576_577delGT		non_coding_transcript_exon_variant	Exon 6 of 12

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ETFA	ENST00000557943.6	c.495_496delGT	p.Ser167CysfsTer7	frameshift_variant	Exon 6 of 12	1	NM_000126.4	ENSP00000452762.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.0000119 AC: 3 AN: 251322 Hom.: 0 AF XY: 0.0000147 AC XY: 2 AN XY: 135816

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: 0.0000264

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000116 AC: 17 AN: 1461466 Hom.: 0 AF XY: 0.0000124 AC XY: 9 AN XY: 727052

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000153

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000508 Hom.: 0

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Multiple acyl-CoA dehydrogenase deficiency Pathogenic:3

Dec 01, 2023

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

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: ETFA c.495_496delGT (p.Ser167CysfsX7) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. The variant allele was found at a frequency of 1.2e-05 in 251322 control chromosomes. To our knowledge, no occurrence of c.495_496delGT in individuals affected with Glutaric Aciduria, Type 2a and no experimental evidence demonstrating its impact on protein function have been reported. Two submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. All submitters classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Sep 24, 2023

Baylor Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jan 09, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Ser167Cysfs*7) in the ETFA gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in ETFA are known to be pathogenic (PMID: 16510302, 23785301). This variant is present in population databases (no rsID available, gnomAD 0.003%). This variant has not been reported in the literature in individuals affected with ETFA-related conditions. ClinVar contains an entry for this variant (Variation ID: 459956). For these reasons, this variant has been classified as Pathogenic. -

ETFA-related disorder Pathogenic:1

Aug 24, 2022

PreventionGenetics, part of Exact Sciences

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The ETFA c.495_496delGT variant is predicted to result in a frameshift and premature protein termination (p.Ser167Cysfs*7). To our knowledge, this variant has not been reported in the literature. It has been reported in 0.0026% of alleles in individuals of European (Non-Finnish) descent in gnomAD (http://gnomad.broadinstitute.org/variant/15-76578777-AAC-A). Frameshift variants in ETFA are expected to be pathogenic, and therefore this variant is interpreted as pathogenic. -

Computational scores

Source: dbNSFP v4.3

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

Publications

LitVar

Other links and lift over

dbSNP: rs1298299792; hg19: chr15-76578777;