rs1555384217

chr15-45368091-C-T

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 (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M218V) has been classified 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/exons	MANE	UniProt
GATM	NM_001482.3	c.654G>A	p.Met218Ile	missense_variant	4/9	ENST00000396659.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GATM	ENST00000396659.8	c.654G>A	p.Met218Ile	missense_variant	4/9	1	NM_001482.3	P1

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

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Feb 03, 2022

Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). 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. ClinVar contains an entry for this variant (Variation ID: 469141). This variant has not been reported in the literature in individuals affected with GATM-related conditions. This variant is not present in population databases (gnomAD no frequency). 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). -

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;.
MutationTaster	Benign	1.0	D;D
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;