rs1554841293

Positions:

• chr10-80285583-A-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The ENST00000372213.8(MAT1A):​c.98T>A​(p.Ile33Asn) 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. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: MAT1A ENST00000372213.8 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 8.95

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.925

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MAT1A	NM_000429.3	c.98T>A	p.Ile33Asn	missense_variant	2/9	ENST00000372213.8	NP_000420.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MAT1A	ENST00000372213.8	c.98T>A	p.Ile33Asn	missense_variant	2/9	1	NM_000429.3	ENSP00000361287	P1
MAT1A	ENST00000455001.1	c.32T>A	p.Ile11Asn	missense_variant	2/5	5		ENSP00000414961

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

MAT1A-related disorder Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Dec 18, 2022

The MAT1A c.98T>A variant is predicted to result in the amino acid substitution p.Ile33Asn. This variant was reported in a study investigating the performance of whole exome sequencing as the primary newborn screen in California. The variant was detected, heterozygous, in one individual who had a positive newborn screen by MS/MS for Hypermethioninemia (Table S5, Adhikari et al. 2020. PubMed ID: 32778825). Although the authors noted that two variants were detected, the identity of the second variant remains unclear. It is also unclear if the individual carrying p.Ile33Asn variant was clinically affected. This variant has not been reported in a large population database (http://gnomad.broadinstitute.org), indicating this variant is rare. Although we suspect that this variant may be pathogenic, at this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Hepatic methionine adenosyltransferase deficiency Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 29, 2017

This sequence change replaces isoleucine with asparagine at codon 33 of the MAT1A protein (p.Ile33Asn). The isoleucine residue is highly conserved and there is a large physicochemical difference between isoleucine and asparagine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with MAT1A-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.97
BayesDel_addAF	Pathogenic	0.36	D
BayesDel_noAF	Pathogenic	0.28
CADD	Pathogenic	30
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.97	D;D
Eigen	Pathogenic	0.99
Eigen_PC	Pathogenic	0.94
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D;D
M_CAP	Pathogenic	0.39	D
MetaRNN	Pathogenic	0.92	D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	3.5	H;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Pathogenic	0.93	D
PROVEAN	Pathogenic	-4.8	D;D
REVEL	Pathogenic	0.89
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	D;.
Vest4		0.89
MutPred		0.72		Gain of disorder (P = 0.0175);.;
MVP		0.79
MPC		2.1
ClinPred		1.0	D
GERP RS		5.9
Varity_R		0.97
gMVP		0.98

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: rs1554841293; hg19: chr10-82045339;