3-49417974-C-T

Variant names:

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PVS1_StrongPM2PP5_Very_Strong

The NM_000481.4(AMT):c.878-1G>A variant causes a splice acceptor, intron change. The variant allele was found at a frequency of 0.00000871 in 1,607,240 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★).

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 31)

Exomes 𝑓: 0.0000076 ( 0 hom. )

Consequence

AMT
NM_000481.4 splice_acceptor, intron

Scores

Splicing: ADA: 1.000

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:9

Conservation

PhyloP100: 6.78

Variant links:

Genes affected

AMT (HGNC:473): (aminomethyltransferase) This gene encodes one of four critical components of the glycine cleavage system. Mutations in this gene have been associated with glycine encephalopathy. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Sep 2011]

AMT links:

ENSG00000283189 (HGNC:):

ENSG00000283189 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 14 ACMG points.

PVS1

Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.12871288 fraction of the gene. Cryptic splice site detected, with MaxEntScore 5.5, offset of 1, new splice context is: ctcatgtgtcattctccaAGgaa. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 3-49417974-C-T is Pathogenic according to our data. Variant chr3-49417974-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 11981.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-49417974-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
AMT	NM_000481.4 link	c.878-1G>A		splice_acceptor_variant, intron_variant	Intron 7 of 8	ENST00000273588.9	NP_000472.2	P48728-1A0A024R2U7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
AMT	ENST00000273588.9 link	c.878-1G>A		splice_acceptor_variant, intron_variant	Intron 7 of 8	1	NM_000481.4	ENSP00000273588.3		P48728-1
ENSG00000283189	ENST00000636166.1 link	c.1115-1G>A		splice_acceptor_variant, intron_variant	Intron 9 of 10	5		ENSP00000490106.1		A0A1B0GUH1

Frequencies

GnomAD3 genomes

AF:

0.0000197

AC:

AN:

152100

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000131

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.000478

GnomAD3 exomes

AF:

0.0000171

AC:

AN:

234492

Hom.:

AF XY:

0.00000783

AC XY:

AN XY:

127654

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000914

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:

0.00000958

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000756

AC:

AN:

1455022

Hom.:

Cov.:

AF XY:

0.00000829

AC XY:

AN XY:

723588

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.000184

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:

0.00000180

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000197

AC:

AN:

152218

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74410

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.000131

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.000473

Alfa

AF:

0.0000281

Hom.:

ExAC

AF:

0.00000825

AC:

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:9

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Glycine encephalopathy

Pathogenic:5

Mar 08, 2018

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: AMT c.878-1G>A is located in a canonical splice-site and is predicted to affect mRNA splicing resulting in a significantly altered protein due to either exon skipping, shortening, or inclusion of intronic material. Several computational tools predict a significant impact on normal splicing: Five predict the variant weakens a 3 acceptor site. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 1.9e-05 in 260824 control chromosomes. c.878-1G>A has been reported in the literature in multiple individuals affected with Glycine Encephalopathy (Non-Ketotic Hyperglycinemia). These data indicate that the variant is very likely to be associated with disease. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014. Based on the evidence outlined above, the variant was classified as pathogenic. -

Oct 31, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change affects an acceptor splice site in intron 7 of the AMT gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in AMT are known to be pathogenic (PMID: 16450403). This variant is present in population databases (rs181134220, gnomAD 0.01%). Disruption of this splice site has been observed in individual(s) with glycine encephalopathy (PMID: 11139253, 12948742; internal data). ClinVar contains an entry for this variant (Variation ID: 11981). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

Sep 16, 2020

Natera, Inc.

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Oct 27, 2021

Myriad Genetics, Inc.

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

NM_000481.3(AMT):c.878-1G>A is a canonical splice variant classified as pathogenic in the context of glycine encephalopathy, AMT-related. c.878-1G>A has been observed in cases with relevant disease (PMID: 12948742, 27362913). Functional assessments of this variant are available in the literature (PMID: 28244183). c.878-1G>A has been observed in population frequency databases (gnomAD: AMR 0.01%). In summary, NM_000481.3(AMT):c.878-1G>A is a canonical splice variant that has been observed more frequently in cases with the relevant disease than in healthy populations. Please note: this variant was assessed in the context of healthy population screening. -

Jul 11, 2013

GeneReviews

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: curation

- -

Glycine encephalopathy 2

Pathogenic:2

Jan 01, 2001

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Apr 30, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided

Pathogenic:1

May 29, 2024

Mayo Clinic Laboratories, Mayo Clinic

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

PM2, PM3, PS3, PS4, PVS1 -

Glycine encephalopathy 1

Pathogenic:1

Feb 03, 2024

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.48

BayesDel_noAF

Pathogenic

0.30

CADD

Pathogenic

DANN

Uncertain

0.99

Eigen

Pathogenic

1.0

Eigen_PC

Pathogenic

0.83

FATHMM_MKL

Pathogenic

0.99

GERP RS

4.8

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.93

SpliceAI score (max)

0.98

Details are displayed if max score is > 0.2

DS_AG_spliceai

0.86

Position offset: -2

DS_AL_spliceai

0.98

Position offset: -1

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