rs747656257

Positions:

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM1PM2PP3

The NM_000156.6(GAMT):c.419C>T(p.Ser140Leu) variant causes a missense change. The variant allele was found at a frequency of 0.0000304 in 1,613,630 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 0.000053 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000028 ( 0 hom. )

Consequence

GAMT
NM_000156.6 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 6.74

Variant links:

Genes affected

GAMT (HGNC:4136): (guanidinoacetate N-methyltransferase) The protein encoded by this gene is a methyltransferase that converts guanidoacetate to creatine, using S-adenosylmethionine as the methyl donor. Defects in this gene have been implicated in neurologic syndromes and muscular hypotonia, probably due to creatine deficiency and accumulation of guanidinoacetate in the brain of affected individuals. Two transcript variants encoding different isoforms have been described for this gene. Pseudogenes of this gene are found on chromosomes 2 and 13. [provided by RefSeq, Feb 2012]

GAMT links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 5 ACMG points.

PM1

In a domain RMT2 (size 223) in uniprot entity GAMT_HUMAN there are 36 pathogenic changes around while only 7 benign (84%) in NM_000156.6

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.824

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
GAMT	NM_000156.6 linkuse as main transcript	c.419C>T	p.Ser140Leu	missense_variant	4/6	ENST00000252288.8	NP_000147.1
GAMT	NM_138924.3 linkuse as main transcript	c.419C>T	p.Ser140Leu	missense_variant	4/5		NP_620279.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
GAMT	ENST00000252288.8 linkuse as main transcript	c.419C>T	p.Ser140Leu	missense_variant	4/6	1	NM_000156.6	ENSP00000252288	P1	Q14353-1

Frequencies

GnomAD3 genomes

AF:

0.0000526

AC:

AN:

152194

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000131

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000621

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000441

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000358

AC:

AN:

251170

Hom.:

AF XY:

0.0000368

AC XY:

AN XY:

135888

show subpopulations

Gnomad AFR exome

AF:

0.0000616

Gnomad AMR exome

AF:

0.0000289

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad SAS exome

AF:

0.000163

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000881

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000281

AC:

AN:

1461436

Hom.:

Cov.:

AF XY:

0.0000316

AC XY:

AN XY:

727036

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.0000447

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.000101

Gnomad4 SAS exome

AF:

0.000185

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000153

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000526

AC:

AN:

152194

Hom.:

Cov.:

AF XY:

0.0000673

AC XY:

AN XY:

74342

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.000131

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.000621

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000441

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000329

Hom.:

Bravo

AF:

0.0000189

ExAC

AF:

0.0000494

AC:

Asia WGS

AF:

0.000289

AC:

AN:

3478

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

CeGaT Center for Human Genetics Tuebingen

Jul 01, 2021

- -

Cerebral creatine deficiency syndrome

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 01, 2022

This sequence change replaces serine, which is neutral and polar, with leucine, which is neutral and non-polar, at codon 140 of the GAMT protein (p.Ser140Leu). This variant is present in population databases (rs747656257, gnomAD 0.01%). This variant has not been reported in the literature in individuals affected with GAMT-related conditions. ClinVar contains an entry for this variant (Variation ID: 328347). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on GAMT protein function. 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. -

Deficiency of guanidinoacetate methyltransferase

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.27

BayesDel_addAF

Uncertain

0.13

BayesDel_noAF

Pathogenic

0.18

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Uncertain

0.67

D;.;.

Eigen

Uncertain

0.57

Eigen_PC

Uncertain

0.44

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.95

D;D;D

M_CAP

Pathogenic

0.64

MetaRNN

Pathogenic

0.82

D;D;D

MetaSVM

Uncertain

0.75

MutationAssessor

Pathogenic

3.4

M;.;M

MutationTaster

Benign

1.0

D;D

PrimateAI

Uncertain

0.67

PROVEAN

Uncertain

-3.0

D;.;D

REVEL

Pathogenic

0.72

Sift

Uncertain

0.018

D;.;D

Sift4G

Uncertain

0.039

D;.;D

Polyphen

1.0

D;.;.

Vest4

0.77

MutPred

0.36

Loss of disorder (P = 0.0098);.;Loss of disorder (P = 0.0098);

MVP

0.94

MPC

0.52

ClinPred

0.88

GERP RS

4.0

Varity_R

0.32

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