19-1399180-G-T

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM1PM2PM5PP3_Strong

The NM_000156.6(GAMT):​c.407C>A​(p.Thr136Lys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,320 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T136M) has been classified as Pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Consequence

GAMT
NM_000156.6 missense

Scores

11
7
1

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 7.97
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 10 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;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr19-1399180-G-A is described in Lovd as [Pathogenic].
PP3
MetaRNN computational evidence supports a deleterious effect, 0.952

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
GAMTNM_000156.6 linkuse as main transcriptc.407C>A p.Thr136Lys missense_variant 4/6 ENST00000252288.8 NP_000147.1 Q14353-1V9HWB2
GAMTNM_138924.3 linkuse as main transcriptc.407C>A p.Thr136Lys missense_variant 4/5 NP_620279.1 Q14353-2

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
GAMTENST00000252288.8 linkuse as main transcriptc.407C>A p.Thr136Lys missense_variant 4/61 NM_000156.6 ENSP00000252288.1 Q14353-1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152202
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000654
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
GnomAD3 exomes
AF:
0.00000398
AC:
1
AN:
251062
Hom.:
0
AF XY:
0.00000736
AC XY:
1
AN XY:
135864
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000289
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
Cov.:
34
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152320
Hom.:
0
Cov.:
33
AF XY:
0.0000134
AC XY:
1
AN XY:
74474
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.0000653
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.00
Gnomad4 OTH
AF:
0.00
ExAC
AF:
0.00000824
AC:
1

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.97
BayesDel_addAF
Pathogenic
0.42
D
BayesDel_noAF
Pathogenic
0.45
CADD
Pathogenic
29
DANN
Uncertain
0.99
DEOGEN2
Pathogenic
0.92
D;.;.
Eigen
Uncertain
0.67
Eigen_PC
Uncertain
0.53
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.91
D;D;D
M_CAP
Pathogenic
0.73
D
MetaRNN
Pathogenic
0.95
D;D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Pathogenic
3.4
M;.;M
PrimateAI
Uncertain
0.68
T
PROVEAN
Pathogenic
-5.4
D;.;D
REVEL
Pathogenic
0.98
Sift
Uncertain
0.0020
D;.;D
Sift4G
Uncertain
0.015
D;.;D
Polyphen
1.0
D;.;.
Vest4
0.95
MutPred
0.77
Gain of methylation at T136 (P = 0.0168);.;Gain of methylation at T136 (P = 0.0168);
MVP
0.99
MPC
0.69
ClinPred
0.98
D
GERP RS
4.0
Varity_R
0.91
gMVP
0.92

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.

Other links and lift over

dbSNP: rs374724533; hg19: chr19-1399179; API