rs758217156

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM1PM2PP3

The NM_000156.6(GAMT):c.472C>T(p.Arg158Cys) variant causes a missense change. The variant allele was found at a frequency of 0.000024 in 1,461,132 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R158S) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.000024 ( 0 hom. )

Consequence

GAMT
NM_000156.6 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 3.96

Publications

2 publications found

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 Gene-Disease associations (from GenCC):

guanidinoacetate methyltransferase deficiency
Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, G2P, Labcorp Genetics (formerly Invitae), ClinGen, Ambry Genetics

GAMT links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

PM1

In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 13 uncertain in NM_000156.6

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.773

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GAMT	NM_000156.6 link	c.472C>T	p.Arg158Cys	missense_variant	Exon 5 of 6	ENST00000252288.8	NP_000147.1	Q14353-1V9HWB2
GAMT	NM_138924.3 link	c.472C>T	p.Arg158Cys	missense_variant	Exon 5 of 5		NP_620279.1	Q14353-2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GAMT	ENST00000252288.8 link	c.472C>T	p.Arg158Cys	missense_variant	Exon 5 of 6	1	NM_000156.6	ENSP00000252288.1		Q14353-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD2 exomes

AF:

0.0000160

AC:

AN:

250780

AF XY:

0.00000736

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000868

Gnomad ASJ exome

AF:

0.00

Gnomad EAS 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:

0.0000240

AC:

AN:

1461132

Hom.:

Cov.:

AF XY:

0.0000234

AC XY:

AN XY:

726864

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.0000671

AC:

AN:

44720

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26134

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.0000116

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

52714

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.0000279

AC:

AN:

1111974

Other (OTH)

AF:

0.00

AC:

AN:

60384

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.499

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

Cov.:

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.00000756

ExAC

AF:

0.0000330

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:1

Breakthrough Genomics, Breakthrough Genomics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:not provided

- -

Cerebral creatine deficiency syndrome

Uncertain:1

Dec 09, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 158 of the GAMT protein (p.Arg158Cys). This variant is present in population databases (rs758217156, gnomAD 0.009%). 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: 544256). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt GAMT protein function with a positive predictive value of 95%. 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

Oct 28, 2019

Natera, Inc.

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.20

BayesDel_addAF

Uncertain

0.073

BayesDel_noAF

Uncertain

0.060

CADD

Pathogenic

(source)

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.88

D;.;.

Eigen

Uncertain

0.52

Eigen_PC

Uncertain

0.40

FATHMM_MKL

Uncertain

0.89

LIST_S2

Uncertain

0.97

D;D;D

M_CAP

Pathogenic

0.74

MetaRNN

Pathogenic

0.77

D;D;D

MetaSVM

Pathogenic

0.81

MutationAssessor

Pathogenic

3.3

M;.;M

PhyloP100

4.0

PrimateAI

Uncertain

0.58

PROVEAN

Pathogenic

-5.0

D;.;D

REVEL

Pathogenic

0.79

Sift

Uncertain

0.0020

D;.;D

Sift4G

Uncertain

0.011

D;.;D

Polyphen

1.0

D;.;.

Vest4

0.51

MutPred

0.49

Gain of ubiquitination at K161 (P = 0.0399);.;Gain of ubiquitination at K161 (P = 0.0399);

MVP

0.99

MPC

0.75

ClinPred

0.91

GERP RS

3.5

Varity_R

0.63

gMVP

0.91

Mutation Taster

=51/49

polymorphism

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over