10-124403821-G-A

Variant names:

• chr10-124403821-G-A
• rs386833617
• NM_000274.4:c.748C>T

Variant summary

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

The NM_000274.4(OAT):​c.748C>T​(p.Arg250*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000958 in 1,461,768 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 Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. R250R) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000096 (0 hom.)
• Consequence: OAT NM_000274.4 stop_gained
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 2.04
• Publications: 4 publications found

Genes affected

OAT (HGNC:8091): (ornithine aminotransferase) This gene encodes the mitochondrial enzyme ornithine aminotransferase, which is a key enzyme in the pathway that converts arginine and ornithine into the major excitatory and inhibitory neurotransmitters glutamate and GABA. Mutations that result in a deficiency of this enzyme cause the autosomal recessive eye disease Gyrate Atrophy. Alternatively spliced transcript variants encoding different isoforms have been described. Related pseudogenes have been defined on the X chromosome. [provided by RefSeq, Jan 2010]

OAT Gene-Disease associations (from GenCC):

• ornithine aminotransferase deficiency

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: ClinGen, Labcorp Genetics (formerly Invitae), G2P, 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 10-124403821-G-A is Pathogenic according to our data. Variant chr10-124403821-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 56135.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000274.4. 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
	OAT	NM_000274.4	MANE Select	c.748C>T	p.Arg250*	stop_gained	Exon 6 of 10	NP_000265.1
	OAT	NM_001322965.2		c.748C>T	p.Arg250*	stop_gained	Exon 6 of 10	NP_001309894.1
	OAT	NM_001322966.2		c.748C>T	p.Arg250*	stop_gained	Exon 7 of 11	NP_001309895.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	OAT	ENST00000368845.6	TSL:1 MANE Select	c.748C>T	p.Arg250*	stop_gained	Exon 6 of 10	ENSP00000357838.5
	OAT	ENST00000539214.5	TSL:1	c.334C>T	p.Arg112*	stop_gained	Exon 5 of 9	ENSP00000439042.1
	OAT	ENST00000467675.5	TSL:5	n.549C>T		non_coding_transcript_exon	Exon 5 of 7

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000795 AC: 2 AN: 251456 AF XY: 0.00000736

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000958 AC: 14 AN: 1461768 Hom.: 0 Cov.: 32 AF XY: 0.00000825 AC XY: 6 AN XY: 727186

African (AFR) AF: 0.00 AC: 0 AN: 33476

American (AMR) AF: 0.0000224 AC: 1 AN: 44718

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39696

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

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53408

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.0000108 AC: 12 AN: 1111932

Other (OTH) AF: 0.0000166 AC: 1 AN: 60382

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000406 Hom.: 0

Bravo AF: 0.00000756

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Ornithine aminotransferase deficiency Pathogenic:3

Juha Muilu Group; Institute for Molecular Medicine Finland (FIMM)

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

Jan 21, 2024

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Oct 15, 2023

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.Arg250*) in the OAT gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in OAT are known to be pathogenic (PMID: 1737786, 23076989). This variant is present in population databases (rs386833617, gnomAD 0.003%). This premature translational stop signal has been observed in individual(s) with gyrate atrophy (PMID: 22182799). ClinVar contains an entry for this variant (Variation ID: 56135). For these reasons, this variant has been classified as Pathogenic.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Pathogenic	0.38
CADD	Pathogenic	41
DANN	Uncertain	1.0
Eigen	Uncertain	0.55
Eigen_PC	Uncertain	0.36
FATHMM_MKL	Uncertain	0.77	D
PhyloP100		2.0
Vest4		0.97
GERP RS		2.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.2
Mutation Taster		=0/200	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.16		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: rs386833617; hg19: chr10-126092390;