rs570476209

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 4P and 2B. PM1PM2BP4_Moderate

The NM_000156.6(GAMT):​c.379G>A​(p.Gly127Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000198 in 1,612,992 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000018 ( 0 hom. )

Consequence

GAMT
NM_000156.6 missense

Scores

3
16

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3B:1

Conservation

PhyloP100: 0.569

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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

PM1
In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 6 uncertain in NM_000156.6
PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.06828219).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
GAMTNM_000156.6 linkc.379G>A p.Gly127Ser missense_variant Exon 3 of 6 ENST00000252288.8 NP_000147.1 Q14353-1V9HWB2
GAMTNM_138924.3 linkc.379G>A p.Gly127Ser missense_variant Exon 3 of 5 NP_620279.1 Q14353-2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
GAMTENST00000252288.8 linkc.379G>A p.Gly127Ser missense_variant Exon 3 of 6 1 NM_000156.6 ENSP00000252288.1 Q14353-1

Frequencies

GnomAD3 genomes
AF:
0.0000329
AC:
5
AN:
152166
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000966
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000655
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000443
AC:
11
AN:
248576
AF XY:
0.0000445
show subpopulations
Gnomad AFR exome
AF:
0.000188
Gnomad AMR exome
AF:
0.000145
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000268
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000185
AC:
27
AN:
1460708
Hom.:
0
Cov.:
32
AF XY:
0.0000248
AC XY:
18
AN XY:
726536
show subpopulations
African (AFR)
AF:
0.000120
AC:
4
AN:
33468
American (AMR)
AF:
0.000134
AC:
6
AN:
44628
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26104
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39694
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86078
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52914
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
0.0000153
AC:
17
AN:
1111690
Other (OTH)
AF:
0.00
AC:
0
AN:
60366
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.458
Heterozygous variant carriers
0
2
4
5
7
9
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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
AF:
0.0000328
AC:
5
AN:
152284
Hom.:
0
Cov.:
32
AF XY:
0.0000134
AC XY:
1
AN XY:
74464
show subpopulations
African (AFR)
AF:
0.0000963
AC:
4
AN:
41544
American (AMR)
AF:
0.0000654
AC:
1
AN:
15298
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5180
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10622
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68024
Other (OTH)
AF:
0.00
AC:
0
AN:
2114
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.555
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.0000416
ExAC
AF:
0.0000577
AC:
7
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3Benign:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Uncertain:1
Jun 22, 2015
Genetic Services Laboratory, University of Chicago
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Uncertain:1
Jun 03, 2019
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Has not been previously published as pathogenic or benign to our knowledge -

Cerebral creatine deficiency syndrome Uncertain:1
Dec 31, 2021
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 127 of the GAMT protein (p.Gly127Ser). This variant is present in population databases (rs570476209, gnomAD 0.02%). 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: 205567). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The serine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. 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 Benign:1
Sep 16, 2020
Natera, Inc.
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.075
BayesDel_addAF
Benign
-0.21
T
BayesDel_noAF
Benign
-0.25
CADD
Benign
11
DANN
Benign
0.97
DEOGEN2
Uncertain
0.65
D;.;.
Eigen
Benign
-0.53
Eigen_PC
Benign
-0.59
FATHMM_MKL
Benign
0.26
N
LIST_S2
Benign
0.73
T;T;T
M_CAP
Uncertain
0.11
D
MetaRNN
Benign
0.068
T;T;T
MetaSVM
Benign
-0.30
T
MutationAssessor
Benign
1.3
L;.;L
PhyloP100
0.57
PrimateAI
Benign
0.34
T
PROVEAN
Uncertain
-2.7
D;.;D
REVEL
Benign
0.21
Sift
Benign
0.15
T;.;T
Sift4G
Benign
0.15
T;.;T
Polyphen
0.017
B;.;.
Vest4
0.26
MutPred
0.38
Gain of glycosylation at G127 (P = 0.0323);.;Gain of glycosylation at G127 (P = 0.0323);
MVP
0.81
MPC
0.16
ClinPred
0.078
T
GERP RS
0.49
PromoterAI
-0.032
Neutral
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.0
Varity_R
0.42
gMVP
0.54
Mutation Taster
=92/8
polymorphism

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

Other links and lift over

dbSNP: rs570476209; hg19: chr19-1399535; API