Genetic Variant GNMT:p.Ser4Ser (chr6-42960779-C-T) – ACMG Classification: Likely_benign (-3 pts)

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM2BP4_ModerateBP6_ModerateBP7

The NM_018960.6(GNMT):c.12C>T(p.Ser4Ser) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000284 in 1,542,254 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★).

Frequency

Genomes: 𝑓 0.0015 ( 1 hom., cov: 34)

Exomes 𝑓: 0.00015 ( 0 hom. )

Consequence

GNMT
NM_018960.6 synonymous

Scores

Clinical Significance

Benign criteria provided, single submitter B:2

Conservation

PhyloP100: 0.773

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 Likely_benign. Variant got -3 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.29).

BP6

Variant 6-42960779-C-T is Benign according to our data. Variant chr6-42960779-C-T is described in ClinVar as [Benign]. Clinvar id is 1168628.Status of the report is criteria_provided_single_submitter, 1 stars.

BP7

Synonymous conserved (PhyloP=0.773 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GNMT	NM_018960.6 link	c.12C>T	p.Ser4Ser	synonymous_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.12C>T	p.Ser4Ser	synonymous_variant	Exon 1 of 6	1	NM_018960.6	ENSP00000361894.3		Q14749

Frequencies

GnomAD3 genomes

AF:

0.00148

AC:

226

AN:

152228

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00514

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000589

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00143

GnomAD3 exomes

AF:

0.000375

AC:

AN:

149264

Hom.:

AF XY:

0.000336

AC XY:

AN XY:

80298

show subpopulations

Gnomad AFR exome

AF:

0.00517

Gnomad AMR exome

AF:

0.000317

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000460

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000506

Gnomad OTH exome

AF:

0.000235

GnomAD4 exome

AF:

0.000151

AC:

210

AN:

1389908

Hom.:

Cov.:

AF XY:

0.000131

AC XY:

AN XY:

684648

show subpopulations

Gnomad4 AFR exome

AF:

0.00502

Gnomad4 AMR exome

AF:

0.000387

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000512

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000130

Gnomad4 OTH exome

AF:

0.000295

GnomAD4 genome

AF:

0.00150

AC:

228

AN:

152346

Hom.:

Cov.:

AF XY:

0.00146

AC XY:

109

AN XY:

74494

show subpopulations

Gnomad4 AFR

AF:

0.00517

Gnomad4 AMR

AF:

0.000588

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00142

Alfa

AF:

0.000425

Hom.:

Bravo

AF:

0.00170

Asia WGS

AF:

0.000577

AC:

AN:

3478

ClinVar

Significance: Benign

Submissions summary: Benign:2

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

GNMT-related disorder

Benign:1

May 27, 2019

PreventionGenetics, part of Exact Sciences

Significance: Likely benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

not provided

Benign:1

Dec 30, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.29

CADD

Benign

DANN

Benign

0.96

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