Genetic Variant GNMT:p.Tyr34Cys (chr6-42960868-A-G) – ACMG Classification: Likely_pathogenic (6 pts)

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1PM2PP3_Moderate

The NM_018960.6(GNMT):c.101A>G(p.Tyr34Cys) variant causes a missense change. The variant allele was found at a frequency of 0.00000707 in 1,555,674 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 34)

Exomes 𝑓: 0.0000064 ( 0 hom. )

Consequence

GNMT
NM_018960.6 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 5.63

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_pathogenic. Variant got 6 ACMG points.

PM1

In a binding_site (size 0) in uniprot entity GNMT_HUMAN

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.911

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GNMT	NM_018960.6 link	c.101A>G	p.Tyr34Cys	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.101A>G	p.Tyr34Cys	missense_variant	Exon 1 of 6	1	NM_018960.6	ENSP00000361894.3		Q14749

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152220

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000413

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

0.00000641

AC:

AN:

1403336

Hom.:

Cov.:

AF XY:

0.00000865

AC XY:

AN XY:

693672

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:

0.000112

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152338

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74506

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.000414

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Feb 28, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.101A>G (p.Y34C) alteration is located in exon 1 (coding exon 1) of the GNMT gene. This alteration results from a A to G substitution at nucleotide position 101, causing the tyrosine (Y) at amino acid position 34 to be replaced by a cysteine (C). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.87

BayesDel_addAF

Pathogenic

0.34

BayesDel_noAF

Pathogenic

0.25

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.87

Eigen

Uncertain

0.63

Eigen_PC

Uncertain

0.57

FATHMM_MKL

Uncertain

0.95

LIST_S2

Uncertain

0.93

M_CAP

Pathogenic

0.67

MetaRNN

Pathogenic

0.91

MetaSVM

Uncertain

0.12

MutationAssessor

Uncertain

2.2

PrimateAI

Pathogenic

0.84

PROVEAN

Pathogenic

-5.7

REVEL

Pathogenic

0.74

Sift

Uncertain

0.0020

Sift4G

Uncertain

0.014

Polyphen

1.0

Vest4

0.93

MutPred

0.49

Loss of MoRF binding (P = 0.084);

MVP

0.89

MPC

2.5

ClinPred

0.99

GERP RS

4.8

Varity_R

0.83

gMVP

0.85

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

No publications associated with this variant yet.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over