19-1397365-T-A

Position:

chr19-1397365-T-A

Variant summary

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

This summary comes from the ClinGen Evidence Repository: The NM_000156.6:c.705A>T variant in GAMT is a missense variant that is predicted to cause the substitution of a lysine by an asparagine at amino acid position 235 (p.Lys235Asn). To our knowledge, this variant has not been reported in the literature and results of functional studies are unavailable. The highest population minor allele frequency in gnomAD v4.1.0. is 0.0004016 (18/44822 alleles) in the East Asian population (none of the population data codes are met). The computational predictor REVEL gives a score of 0.342 which is neither above nor below the thresholds predicting a damaging (>0.644) or benign (<0.29) impact on GAMT function. There is a ClinVar entry for this variant (Variation ID: 2137773). In summary, this variant meets the criteria to be classified as a variant of uncertain significance for GAMT deficiency. GAMT-specific ACMG/AMP codes met, as specified by the ClinGen Cerebral Creatine Deficiency Syndromes VCEP (Specifications Version 2.0.0): no criteria met.(Classification approved by the ClinGen Creatine Deficiency Syndromes Variant Curation Expert Panel on September 11, 2024). LINK:https://erepo.genome.network/evrepo/ui/classification/CA9043527/MONDO:0012999/026

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000013 ( 0 hom. )

Consequence

GAMT
ENST00000252288.8 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:1

Conservation

PhyloP100: 0.564

Variant links:

Genes affected

GAMT (HGNC:4136): (guanidinoacetate N-methyltransferase) The protein encoded by this gene is a methyltransferase that converts guanidoacetate to creatine, using S-adenosylmethionine as the methyl donor. Defects in this gene have been implicated in neurologic syndromes and muscular hypotonia, probably due to creatine deficiency and accumulation of guanidinoacetate in the brain of affected individuals. Two transcript variants encoding different isoforms have been described for this gene. Pseudogenes of this gene are found on chromosomes 2 and 13. [provided by RefSeq, Feb 2012]

GAMT links:

GAMT (HGNC:):

GAMT links:

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 0 ACMG points.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
GAMT	NM_000156.6 linkuse as main transcript	c.705A>T	p.Lys235Asn	missense_variant	6/6	ENST00000252288.8	NP_000147.1	Q14353-1V9HWB2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	UniProt
GAMT	ENST00000252288.8 linkuse as main transcript	c.705A>T	p.Lys235Asn	missense_variant	6/6	1	NM_000156.6	ENSP00000252288.1	Q14353-1
GAMT	ENST00000640762.1 linkuse as main transcript	c.636A>T	p.Lys212Asn	missense_variant	6/6	5		ENSP00000492031.1	A0A1W2PR36
GAMT	ENST00000640164.1 linkuse as main transcript	n.*18A>T		downstream_gene_variant		2

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152122

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000386

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000571

AC:

AN:

245328

Hom.:

AF XY:

0.0000599

AC XY:

AN XY:

133458

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000713

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.000167

GnomAD4 exome

AF:

0.0000130

AC:

AN:

1459158

Hom.:

Cov.:

AF XY:

0.0000110

AC XY:

AN XY:

725914

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.000404

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

9.00e-7

Gnomad4 OTH exome

AF:

0.0000332

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152240

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74422

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000387

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000712

Hom.:

Bravo

AF:

0.00000756

ExAC

AF:

0.0000330

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Inborn genetic diseases

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Feb 05, 2024

The c.705A>T (p.K235N) alteration is located in exon 6 (coding exon 6) of the GAMT gene. This alteration results from a A to T substitution at nucleotide position 705, causing the lysine (K) at amino acid position 235 to be replaced by an asparagine (N). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Cerebral creatine deficiency syndrome

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 31, 2024

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.84

BayesDel_addAF

Benign

-0.27

BayesDel_noAF

Benign

-0.26

CADD

Benign

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.71

D;.

Eigen

Benign

0.0026

Eigen_PC

Benign

-0.11

FATHMM_MKL

Benign

0.56

LIST_S2

Benign

0.42

T;T

M_CAP

Uncertain

0.15

MetaRNN

Benign

0.32

T;T

MetaSVM

Uncertain

0.35

MutationAssessor

Uncertain

2.3

M;.

MutationTaster

Benign

1.0

PROVEAN

Uncertain

-2.7

D;.

REVEL

Uncertain

0.34

Sift

Uncertain

0.0030

D;.

Sift4G

Pathogenic

0.0

D;.

Polyphen

1.0

D;.

Vest4

0.52

MutPred

0.17

Loss of methylation at K235 (P = 0.0037);.;

MVP

0.93

ClinPred

0.50

GERP RS

1.4

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.53

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over