Genetic Variant GNMT:p.Thr38Asn (chr6-42960880-C-A) – ACMG Classification: Uncertain_significance (1 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2BP4

The NM_018960.6(GNMT):c.113C>A(p.Thr38Asn) variant causes a missense change. The variant allele was found at a frequency of 0.00000713 in 1,401,678 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 34)

Exomes 𝑓: 0.0000071 ( 0 hom. )

Consequence

GNMT
NM_018960.6 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 4.35

Variant links:

Genes affected

GNMT (HGNC:4415): (glycine N-methyltransferase) The protein encoded by this gene is an enzyme that catalyzes the conversion of S-adenosyl-L-methionine (along with glycine) to S-adenosyl-L-homocysteine and sarcosine. This protein is found in the cytoplasm and acts as a homotetramer. Defects in this gene are a cause of GNMT deficiency (hypermethioninemia). Alternative splicing results in multiple transcript variants. Naturally occurring readthrough transcription occurs between the upstream CNPY3 (canopy FGF signaling regulator 3) gene and this gene and is represented with GeneID:107080644. [provided by RefSeq, Jan 2016]

GNMT links:

CNPY3-GNMT (HGNC:):

CNPY3-GNMT links:

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 1 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.3549674).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GNMT	NM_018960.6 link	c.113C>A	p.Thr38Asn	missense_variant	Exon 1 of 6	ENST00000372808.4	NP_061833.1	Q14749V9HW60

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GNMT	ENST00000372808.4 link	c.113C>A	p.Thr38Asn	missense_variant	Exon 1 of 6	1	NM_018960.6	ENSP00000361894.3		Q14749

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000671

AC:

AN:

149060

Hom.:

AF XY:

0.0000123

AC XY:

AN XY:

81562

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000396

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000713

AC:

AN:

1401678

Hom.:

Cov.:

AF XY:

0.0000130

AC XY:

AN XY:

692722

show subpopulations

Gnomad4 AFR exome

AF:

0.0000312

Gnomad4 AMR exome

AF:

0.0000273

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:

0.00000645

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not provided

Uncertain:1

Jul 29, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant¬¨‚Ä†is likely to be tolerated. This variant has not been reported in the literature in individuals affected with GNMT-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces threonine, which is neutral and polar, with asparagine, which is neutral and polar, at codon 38 of the GNMT protein (p.Thr38Asn). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.30

BayesDel_addAF

Benign

-0.0019

BayesDel_noAF

Benign

-0.24

CADD

Uncertain

DANN

Benign

0.95

DEOGEN2

Benign

0.36

Eigen

Benign

-0.083

Eigen_PC

Benign

0.077

FATHMM_MKL

Uncertain

0.92

LIST_S2

Uncertain

0.92

M_CAP

Pathogenic

0.36

MetaRNN

Benign

0.35

MetaSVM

Benign

-0.83

MutationAssessor

Benign

1.8

PrimateAI

Pathogenic

0.86

PROVEAN

Benign

-0.64

REVEL

Benign

0.23

Sift

Benign

0.25

Sift4G

Benign

0.36

Polyphen

0.0080

Vest4

0.49

MutPred

0.43

Loss of phosphorylation at T38 (P = 0.0262);

MVP

0.72

MPC

1.2

ClinPred

0.59

GERP RS

4.7

Varity_R

0.38

gMVP

0.76

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

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