rs376982466

chr15-45368204-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM1 PP3

The NM_001482.3(GATM):c.541G>A(p.Glu181Lys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000185 in 1,461,814 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 (★★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.000018 (0 hom.)
• Consequence: GATM NM_001482.3 missense
• Clinical Significance: Uncertain significance reviewed by expert panel U:2 O: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.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 4 uncertain in NM_001482.3
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.836

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GATM	NM_001482.3	c.541G>A	p.Glu181Lys	missense_variant	4/9	ENST00000396659.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GATM	ENST00000396659.8	c.541G>A	p.Glu181Lys	missense_variant	4/9	1	NM_001482.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251386 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135866

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

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: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000185 AC: 27 AN: 1461814 Hom.: 0 Cov.: 32 AF XY: 0.0000165 AC XY: 12 AN XY: 727214

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000198

Gnomad4 OTH exome AF: 0.0000662

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ESP6500AA AF: 0.000227 AC: 1

ESP6500EA AF: 0.00 AC: 0

ExAC AF: 0.00000824 AC: 1

EpiCase AF: 0.00

EpiControl AF: 0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2 Other:1

Revision: reviewed by expert panel

Submissions by phenotype

Arginine:glycine amidinotransferase deficiency Uncertain:2

Uncertain significance, reviewed by expert panel	curation	ClinGen Cerebral Creatine Deficiency Syndromes Variant Curation Expert Panel, ClinGen	Jan 24, 2023	The NM_001482.3:c.541G>A variant in GATM is a missense variant that is predicted to result in the substitution of glutamine by lysine at amino acid 181 (p.Glu181Lys). The highest population minor allele frequency for this variant in gnomAD v2.1.1 is 0.00001 (1/113714 alleles) in the European (non-Finnish) population, which is lower than the ClinGen CCDS VCEP’s threshold for PM2_Supporting (<0.000055), meeting this criterion (PM2_Supporting). When overexpressed in HeLa cells, the variant resulted in <15% wild-type enzyme activity (PMID: 27233232). The computational predictor REVEL gives a score of 0.608, which neither predicts a damaging nor a benign inpact on AGAT function. To our knowledge, this variant has not been reported in an individual with AGAT deficiency in the published literature. There is a ClinVar entry for this variant (Variation ID: 225914). In summary, this variant meets the criteria to be classified as a variant of uncertain significance for AGAT deficiency. GATM-specific ACMG/AMP criteria applied, as specified by the ClinGen CCDS VCEP (Specifications Version 1.1.0): PS3_Supporting, PM2_Supporting. (Classification approved by the ClinGen CCDS VCEP on January 24, 2023). -
Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Oct 04, 2023	This sequence change replaces glutamic acid, which is acidic and polar, with lysine, which is basic and polar, at codon 181 of the GATM protein (p.Glu181Lys). This variant is present in population databases (rs376982466, gnomAD 0.0009%). 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: 225914). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt GATM protein function. Experimental studies have shown that this missense change affects GATM function (PMID: 27233232). 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. -

not provided Other:1

not provided, no classification provided

in vitro

Hospital for Sick Children

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.30	D
BayesDel_noAF	Pathogenic	0.20
Cadd	Pathogenic	32
Dann	Pathogenic	1.0
DEOGEN2	Uncertain	0.79	D;.;.
Eigen	Pathogenic	0.84
Eigen_PC	Pathogenic	0.81
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.99	D;D;D
M_CAP	Uncertain	0.086	D
MetaRNN	Pathogenic	0.84	D;D;D
MetaSVM	Benign	-0.36	T
MutationAssessor	Uncertain	2.6	M;M;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.75	T
PROVEAN	Uncertain	-4.0	D;D;D
REVEL	Uncertain	0.61
Sift	Pathogenic	0.0	D;D;D
Sift4G	Pathogenic	0.0	D;D;.
Polyphen		1.0	D;D;.
Vest4		0.98
MVP		0.73
MPC		1.8
ClinPred		1.0	D
GERP RS		5.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.91
gMVP		1.0

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: rs376982466; hg19: chr15-45660402; COSMIC: COSV67541445; COSMIC: COSV67541445;