Genetic Variant MAT1A:p.Arg264His (chr10-80275177-C-T) – ACMG Classification: Pathogenic (14 pts)

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PM2PP3_StrongPP5_Very_Strong

The NM_000429.3(MAT1A):c.791G>A(p.Arg264His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,148 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 13/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

MAT1A
NM_000429.3 missense

Scores

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:6

Conservation

PhyloP100: 7.57

Variant links:

Genes affected

MAT1A (HGNC:6903): (methionine adenosyltransferase 1A) This gene catalyzes a two-step reaction that involves the transfer of the adenosyl moiety of ATP to methionine to form S-adenosylmethionine and tripolyphosphate, which is subsequently cleaved to PPi and Pi. S-adenosylmethionine is the source of methyl groups for most biological methylations. The encoded protein is found as a homotetramer (MAT I) or a homodimer (MAT III) whereas a third form, MAT II (gamma), is encoded by the MAT2A gene. Mutations in this gene are associated with methionine adenosyltransferase deficiency. [provided by RefSeq, Jul 2008]

MAT1A links:

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ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 14 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.993

PP5

Variant 10-80275177-C-T is Pathogenic according to our data. Variant chr10-80275177-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 1208.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
MAT1A	NM_000429.3 link	c.791G>A	p.Arg264His	missense_variant	Exon 7 of 9	ENST00000372213.8	NP_000420.1	Q00266

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
MAT1A	ENST00000372213.8 link	c.791G>A	p.Arg264His	missense_variant	Exon 7 of 9	1	NM_000429.3	ENSP00000361287.3	Q00266
MAT1A	ENST00000480845.1 link	n.23G>A		non_coding_transcript_exon_variant	Exon 1 of 5	3
MAT1A	ENST00000485270.5 link	n.303G>A		non_coding_transcript_exon_variant	Exon 1 of 3	2

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1461148

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

726834

show subpopulations

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:

8.99e-7

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Hepatic methionine adenosyltransferase deficiency

Pathogenic:4

Dec 26, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 264 of the MAT1A protein (p.Arg264His). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This missense change has been observed in individuals with autosomal dominant hypermethioninemia (PMID: 9042912, 18500573, 23430947, 24445979, 25638462). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 1208). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt MAT1A protein function with a positive predictive value of 80%. Experimental studies have shown that this missense change affects MAT1A function (PMID: 9042912, 11278456, 23425511). For these reasons, this variant has been classified as Pathogenic. -

Mar 01, 1997

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Neonatal Disease Screening Center, Medical Genetics Center, Huaihua City Maternal and Child Health Care Hospital

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

PS3+PS4+PM2_P+PP1_S+PP3+PP4 -

May 31, 2023

Revvity Omics, Revvity

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided

Pathogenic:2

Sep 12, 2024

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Observed frequently in unrelated patients from different ethnic backgrounds with autosomal dominant inheritance of methionine adenosyltransferase I/III (MAT I/III) deficiency (PMID: 23993429, 9042912, 10677294, 18500573, 15935930); R264/R264H MAT alpha-1 heterodimers are enzymatically inactive; therefore, R264H has a dominant negative effect on the MAT enzyme (PMID: 9042912); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 15935930, 25762406, 27671891, 28748147, 26933843, 18500573, 10677294, 24231718, 11278456, 10674710, 22951388, 29186975, 31641591, 32335878, 36704196, 38582244, 32778825, 34948004, 32496220, 35281663, 32980525, 35760084, 38784038, 38535129, 37817461, 38061323, 23993429, 9042912) -

Jan 01, 2021

CeGaT Center for Human Genetics Tuebingen

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.99

BayesDel_addAF

Pathogenic

0.56

BayesDel_noAF

Pathogenic

0.57

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.99

Eigen

Pathogenic

1.1

Eigen_PC

Pathogenic

0.92

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Pathogenic

0.99

M_CAP

Pathogenic

0.70

MetaRNN

Pathogenic

0.99

MetaSVM

Pathogenic

1.0

MutationAssessor

Pathogenic

4.4

PrimateAI

Pathogenic

0.89

PROVEAN

Pathogenic

-4.9

REVEL

Pathogenic

0.96

Sift

Pathogenic

0.0

Sift4G

Pathogenic

0.0

Polyphen

1.0

Vest4

0.95

MutPred

0.98

Loss of methylation at R264 (P = 0.0587);

MVP

0.95

MPC

1.7

ClinPred

1.0

GERP RS

4.9

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.94

gMVP

0.97

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over