15-45362124-C-T

Variant summary

Our verdict is Benign. Variant got -11 ACMG points: 0P and 11B. BP4_Moderate BP6_Very_Strong BP7

The NM_001482.3(GATM):c.1257G>A(p.Gln419=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000048 in 1,459,224 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000048 (1 hom.)
• Consequence: GATM NM_001482.3 synonymous
• Clinical Significance: Likely benign reviewed by expert panel B:4
• Conservation: PhyloP100: 1.67

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 Benign. Variant got -11 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.31).
• BP6: Variant 15-45362124-C-T is Benign according to our data. Variant chr15-45362124-C-T is described in ClinVar as [Likely_benign]. Clinvar id is 509542.Status of the report is reviewed_by_expert_panel, 3 stars.
• BP7: Synonymous conserved (PhyloP=1.67 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GATM	NM_001482.3	c.1257G>A	p.Gln419=	synonymous_variant	9/9	ENST00000396659.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GATM	ENST00000396659.8	c.1257G>A	p.Gln419=	synonymous_variant	9/9	1	NM_001482.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000797 AC: 2 AN: 250786 Hom.: 0 AF XY: 0.0000147 AC XY: 2 AN XY: 135628

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: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000884

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000480 AC: 7 AN: 1459224 Hom.: 1 Cov.: 27 AF XY: 0.00000826 AC XY: 6 AN XY: 726206

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000464

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

EpiCase AF: 0.00

EpiControl AF: 0.0000593

ClinVar

Significance: Likely benign

Submissions summary: Benign:4

Revision: reviewed by expert panel

Submissions by phenotype

Arginine:glycine amidinotransferase deficiency Benign:2

Likely benign, criteria provided, single submitter	clinical testing	Invitae	Jan 22, 2023	- -
Likely benign, reviewed by expert panel	curation	ClinGen Cerebral Creatine Deficiency Syndromes Variant Curation Expert Panel, ClinGen	Jun 06, 2022	The NM_001482.3:c.1257G>A (p.Gln419=) variant in GATM is a synonymous (silent) variant that is not predicted by SpliceAI to impact splicing. In addition, it occurs at a nucleotide that is not highly conserved as shown by PhyloP (BP7). The highest population minor allele frequency in gnomAD v2.1.1 is 0.00003 (1/30612 alleles) in the South Asian population, which is lower than the ClinGen CCDS VCEP’s threshold for PM2_Supporting (<0.000055), meeting this criterion (PM2_Supporting). The computational splicing predictor SpliceAI gives a score of 0.0 for donor and acceptor loss suggesting that the variant has no impact on splicing (BP4). There is a ClinVar entry for this variant (Variation ID: 509542). Although this variant is rare (meeting PM2_Supporting), it has been classified as likely benign by the ClinGen CCDS VCEP based on the recommendation of Richards et al (PMID: 25741868) because it is a synonymous variant, the altered nucleotide is not highly conserved, computational prediction suggests no impact on splicing, and there is no additional evidence to suggest that the variant is disease-causing. GATM-specific ACMG/AMP criteria applied, as specified by the CCDS VCEP (Specifications Version 1.1.0): PM2_Supporting, BP4, BP7. (Classification approved by the ClinGen CCDS VCEP on June 6, 2022). -

not specified Benign:1

Likely benign, criteria provided, single submitter

clinical testing

GeneDx

May 10, 2017

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

Arginine:glycine amidinotransferase deficiency;C4551503:Fanconi renotubular syndrome 1 Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Oct 15, 2021

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.31
Cadd	Benign	8.9
Dann	Benign	0.73

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: rs774881489; hg19: chr15-45654322;