rs121965045

Positions:

• chr10-124400875-C-G

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM2 PP3_Strong PP5

The NM_000274.4(OAT):​c.1124G>C​(p.Gly375Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency: Genomes: not found (cov: 33)
• Consequence: OAT NM_000274.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:1
• Conservation: PhyloP100: 7.50

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]

ACMG classification

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.991
• PP5: Variant 10-124400875-C-G is Pathogenic according to our data. Variant chr10-124400875-C-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 159.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=1}. Variant chr10-124400875-C-G is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
OAT	NM_000274.4	c.1124G>C	p.Gly375Ala	missense_variant	9/10	ENST00000368845.6	NP_000265.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
OAT	ENST00000368845.6	c.1124G>C	p.Gly375Ala	missense_variant	9/10	1	NM_000274.4	ENSP00000357838	P1
OAT	ENST00000539214.5	c.710G>C	p.Gly237Ala	missense_variant	8/9	1		ENSP00000439042
OAT	ENST00000471127.1	n.634G>C		non_coding_transcript_exon_variant	3/4	2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000378

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Ornithine aminotransferase deficiency Pathogenic:1 Uncertain:1

Pathogenic, no assertion criteria provided	literature only	OMIM	Feb 15, 1992	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jul 14, 2022	Experimental studies are conflicting or provide insufficient evidence to determine the effect of this variant on OAT function (PMID: 1737786). 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. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). ClinVar contains an entry for this variant (Variation ID: 159). This missense change has been observed in individual(s) with OAT-related conditions (PMID: 1737786). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces glycine, which is neutral and non-polar, with alanine, which is neutral and non-polar, at codon 375 of the OAT protein (p.Gly375Ala). -

Retinal dystrophy Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Blueprint Genetics

Apr 20, 2018

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.94
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Pathogenic	0.59
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.98	.;D
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.87
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D;D
M_CAP	Pathogenic	0.65	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	3.9	.;H
MutationTaster	Benign	1.0	A;A
PrimateAI	Pathogenic	0.81	D
PROVEAN	Pathogenic	-5.7	D;D
REVEL	Pathogenic	0.97
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	.;D
Vest4		0.98
MutPred		0.99		.;Gain of sheet (P = 0.0827);
MVP		1.0
MPC		0.84
ClinPred		1.0	D
GERP RS		5.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.98
gMVP		0.97

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: rs121965045; hg19: chr10-126089444;