rs80338738

Variant names:

• chr15-45369325-C-A
• rs80338738
• NM_001482.3:c.484+1G>T

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PVS1 PM2_Supporting PM3_Supporting PP4

This summary comes from the ClinGen Evidence Repository: The NM_001482.3:c.484+1G>T variant in GATM occurs within the canonical splice donor site of intron 3. It was shown by RT-PCR to cause skipping of exon 3, resulting in a frameshift, premature termination codon, and nonsense-mediated decay (PMID:22386973) (PVS1). One individual who is homozygous for the variant has been reported with significantly decreased creatine peak on H1-MRS, nondetectable enzyme activity in cultured lymphoblasts, and low GAA in plasma and low creatine in plasma (PP4_Strong, PM3_Supporting). The highest population minor allele frequency in gnomAD v2.1.1 is 0.00005 (1/18394) in the East Asian population, which is lower than the ClinGen CCDS VCEP's threshold for PM2_Supporting (<0.0004), meeting this criterion (PM2_Supporting). The variant is noted in ClinVar (Variation ID: 21299). In summary, this variant meets the criteria to be classified as pathogenic for AGAT deficiency. GATM-specific ACMG/AMP codes met, as specified by the ClinGen Cerebral Creatine Deficiency Syndromes VCEP (Specifications Version 1.1.0): PVS1, PP4_Strong, PM3_Supporting, PM2_Supporting.(Classification approved by the ClinGen CCDS VCEP on June 6, 2022). LINK:https://erepo.genome.network/evrepo/ui/classification/CA341869/MONDO:0012996/025

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: GATM NM_001482.3 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic reviewed by expert panel P:3
• Conservation: PhyloP100: 7.48
• Publications: 3 publications found

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]

GATM Gene-Disease associations (from GenCC):

• AGAT deficiency

  Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, Orphanet, Ambry Genetics, G2P
• Fanconi renotubular syndrome 1

  Inheritance: AD Classification: MODERATE Submitted by: Ambry Genetics
• primary Fanconi syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 11 ACMG points.

• PVS1: For more information check the summary or visit ClinGen Evidence Repository.
• PM2: For more information check the summary or visit ClinGen Evidence Repository.
• PM3: For more information check the summary or visit ClinGen Evidence Repository.
• PP4: For more information check the summary or visit ClinGen Evidence Repository.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001482.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GATM	NM_001482.3	MANE Select	c.484+1G>T		splice_donor intron	N/A	NP_001473.1
	GATM	NM_001321015.2		c.97+1G>T		splice_donor intron	N/A	NP_001307944.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GATM	ENST00000396659.8	TSL:1 MANE Select	c.484+1G>T		splice_donor intron	N/A	ENSP00000379895.3
	GATM	ENST00000558362.5	TSL:1	n.2140+1G>T		splice_donor intron	N/A
	GATM	ENST00000887717.1		c.484+1G>T		splice_donor intron	N/A	ENSP00000557776.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251388 AF XY: 0.00000736

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000544

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460852 Hom.: 0 Cov.: 30 AF XY: 0.00000138 AC XY: 1 AN XY: 726844

African (AFR) AF: 0.00 AC: 0 AN: 33454

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26128

East Asian (EAS) AF: 0.0000252 AC: 1 AN: 39682

South Asian (SAS) AF: 0.00 AC: 0 AN: 86230

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53404

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111102

Other (OTH) AF: 0.00 AC: 0 AN: 60360

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ClinVar

ClinVar submissions as Germline

Significance: Pathogenic

Revision: reviewed by expert panel

Pathogenic	VUS	Benign	Condition
2	-	-	Arginine:glycine amidinotransferase deficiency (2)
1	-	-	Arginine:glycine amidinotransferase deficiency;C4551503:Fanconi renotubular syndrome 1 (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.51	D
BayesDel_noAF	Pathogenic	0.42
CADD	Pathogenic	34
DANN	Uncertain	0.99
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.1
FATHMM_MKL	Pathogenic	0.99	D
PhyloP100		7.5
GERP RS		5.3
Mutation Taster		=0/100	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_DL_spliceai		1.0		Position offset: 1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs80338738; hg19: chr15-45661523;