2-240873025-AC-ACC

Variant names:

• chr2-240873025-A-AC
• rs180177241
• NM_000030.3:c.577dupC

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000030.3(AGXT):​c.577dupC​(p.Leu193ProfsTer32) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,620 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: AGXT NM_000030.3 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:5
• Conservation: PhyloP100: -0.229
• Publications: 2 publications found

Genes affected

AGXT (HGNC:341): (alanine--glyoxylate aminotransferase) This gene is expressed only in the liver and the encoded protein is localized mostly in the peroxisomes, where it is involved in glyoxylate detoxification. Mutations in this gene, some of which alter subcellular targetting, have been associated with type I primary hyperoxaluria. [provided by RefSeq, Jul 2008]

AGXT Gene-Disease associations (from GenCC):

• alanine glyoxylate aminotransferase deficiency

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• primary hyperoxaluria type 1

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Myriad Women’s Health, Ambry Genetics, Labcorp Genetics (formerly Invitae), Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 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 2-240873025-A-AC is Pathogenic according to our data. Variant chr2-240873025-A-AC is described in ClinVar as Pathogenic. ClinVar VariationId is 204192.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000030.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	AGXT	NM_000030.3	MANE Select	c.577dupC	p.Leu193ProfsTer32	frameshift	Exon 5 of 11	NP_000021.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	AGXT	ENST00000307503.4	TSL:1 MANE Select	c.577dupC	p.Leu193ProfsTer32	frameshift	Exon 5 of 11	ENSP00000302620.3
	AGXT	ENST00000472436.1	TSL:2	n.597dupC		non_coding_transcript_exon	Exon 5 of 5
	AGXT	ENST00000476698.1	TSL:5	n.314dupC		non_coding_transcript_exon	Exon 2 of 4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461620 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727152

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44712

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26124

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

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86250

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53276

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5764

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111930

Other (OTH) AF: 0.00 AC: 0 AN: 60386

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Primary hyperoxaluria, type I Pathogenic:3

Nov 27, 2014

Clinical Biochemistry Laboratory, Health Services Laboratory

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: research

Aug 20, 2024

Revvity Omics, Revvity

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Nov 28, 2023

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Primary hyperoxaluria Pathogenic:1

Mar 02, 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: AGXT c.577dupC (p.Leu193ProfsX32) 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. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant was absent in 249482 control chromosomes. c.577dupC has been reported in the literature in multiple individuals affected with Primary Hyperoxaluria Type 1 (Williams_2009, Williams_2015, Abid_2022). These data indicate that the variant is very likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. One (other) submitter has provided a clinical-significance assessment for this variant to ClinVar after 2014, and classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic.

not provided Pathogenic:1

Jun 11, 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.Leu193Profs*32) in the AGXT gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in AGXT are known to be pathogenic (PMID: 19479957). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with primary hyperoxaluria (PMID: 19479957, 37464296). ClinVar contains an entry for this variant (Variation ID: 204192). For these reasons, this variant has been classified as Pathogenic.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		-0.23
Mutation Taster		=1/199	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs180177241; hg19: chr2-241812442;