rs1555384217

Variant names:

• chr15-45368091-C-T
• rs1555384217
• NM_001482.3:c.654G>A

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP3

The NM_001482.3(GATM):​c.654G>A​(p.Met218Ile) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: GATM NM_001482.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.48

Genes affected

GATM (HGNC:4175): (glycine amidinotransferase) This gene encodes a mitochondrial enzyme that belongs to the amidinotransferase family. This enzyme is involved in creatine biosynthesis, whereby it catalyzes the transfer of a guanido group from L-arginine to glycine, resulting in guanidinoacetic acid, the immediate precursor of creatine. Mutations in this gene cause arginine:glycine amidinotransferase deficiency, an inborn error of creatine synthesis characterized by cognitive disability, language impairment, and behavioral disorders. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.767

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GATM	NM_001482.3	c.654G>A	p.Met218Ile	missense_variant	Exon 4 of 9	ENST00000396659.8	NP_001473.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GATM	ENST00000396659.8	c.654G>A	p.Met218Ile	missense_variant	Exon 4 of 9	1	NM_001482.3	ENSP00000379895.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

Alfa AF: 0.0135 Hom.: 0

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Arginine:glycine amidinotransferase deficiency Uncertain:1

Nov 13, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces methionine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 218 of the GATM protein (p.Met218Ile). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with GATM-related conditions. ClinVar contains an entry for this variant (Variation ID: 469141). 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 GATM 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.24	D
BayesDel_noAF	Uncertain	0.11
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.45	T;.;.
Eigen	Pathogenic	0.79
Eigen_PC	Pathogenic	0.77
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.98	D;D;D
M_CAP	Benign	0.031	D
MetaRNN	Pathogenic	0.77	D;D;D
MetaSVM	Benign	-0.60	T
MutationAssessor	Uncertain	2.8	M;M;.
PrimateAI	Uncertain	0.53	T
PROVEAN	Benign	-2.0	N;N;N
REVEL	Uncertain	0.40
Sift	Uncertain	0.027	D;D;D
Sift4G	Uncertain	0.044	D;D;.
Polyphen		1.0	D;D;.
Vest4		0.93
MutPred		0.55		Loss of ubiquitination at K215 (P = 0.0566);Loss of ubiquitination at K215 (P = 0.0566);.;
MVP		0.57
MPC		1.4
ClinPred		0.97	D
GERP RS		5.5
Varity_R		0.65
gMVP		0.94

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

Other links and lift over

dbSNP: rs1555384217; hg19: chr15-45660289;