rs558998633

Variant names:

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_000481.4(AMT):c.496C>T(p.Gln166*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000131 in 152,246 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Consequence

AMT
NM_000481.4 stop_gained

Scores

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:4

Conservation

PhyloP100: 0.326

Publications

0 publications found

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 Gene-Disease associations (from GenCC):

glycine encephalopathy
Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: ClinGen, Labcorp Genetics (formerly Invitae), Myriad Women’s Health
glycine encephalopathy 2
Inheritance: AR Classification: DEFINITIVE Submitted by: G2P
infantile glycine encephalopathy
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
neonatal glycine encephalopathy
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
atypical glycine encephalopathy
Inheritance: Unknown Classification: SUPPORTIVE Submitted by: Orphanet

AMT links:

ENSG00000283189 (HGNC:):

ENSG00000283189 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 18 ACMG points.

PVS1

Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 3-49419764-G-A is Pathogenic according to our data. Variant chr3-49419764-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 557617.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
AMT	NM_000481.4 link	c.496C>T	p.Gln166*	stop_gained	Exon 5 of 9	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.496C>T	p.Gln166*	stop_gained	Exon 5 of 9	1	NM_000481.4	ENSP00000273588.3		P48728-1
ENSG00000283189	ENST00000636166.1 link	c.733C>T	p.Gln245*	stop_gained	Exon 7 of 11	5		ENSP00000490106.1		A0A1B0GUH1

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152128

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:

0.00

Gnomad SAS

AF:

0.000207

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD4 exome

Cov.:

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152246

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74442

show subpopulations

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR)

AF:

0.00

AC:

AN:

41552

American (AMR)

AF:

0.00

AC:

AN:

15280

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5182

South Asian (SAS)

AF:

0.000207

AC:

AN:

4828

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10606

Middle Eastern (MID)

AF:

0.00

AC:

AN:

292

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68016

Other (OTH)

AF:

0.00

AC:

AN:

2106

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.00000000770867), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.400

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.00000378

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Glycine encephalopathy

Pathogenic:3

Oct 27, 2021

Baylor Genetics

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

May 22, 2022

3billion

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The variant is not observed in the gnomAD v2.1.1 dataset. Stop-gained (nonsense): predicted to result in a loss or disruption of normal protein function through nonsense-mediated decay (NMD) or protein truncation. Multiple pathogenic variants are reported downstream of the variant. The variant has been reported to be associated with AMT related disorder (ClinVar ID: VCV000557617 / PMID: 26179960). Therefore, this variant is classified as pathogenic according to the recommendation of ACMG/AMP guideline. -

Feb 11, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change creates a premature translational stop signal (p.Gln166*) in the AMT gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in AMT are known to be pathogenic (PMID: 16450403). This variant is present in population databases (rs558998633, gnomAD 0.003%). This premature translational stop signal has been observed in individual(s) with nonketotic hyperglycinemia (PMID: 26179960). ClinVar contains an entry for this variant (Variation ID: 557617). 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. -

Glycine encephalopathy 1

Pathogenic:1

Apr 03, 2018

Counsyl

Significance:Likely pathogenic

Review Status:no assertion criteria provided

Collection Method:clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.55

BayesDel_noAF

Uncertain

0.040

CADD

Pathogenic

(source)

DANN

Uncertain

0.98

Eigen

Benign

-0.11

Eigen_PC

Benign

-0.39

FATHMM_MKL

Benign

0.062

PhyloP100

0.33

Vest4

0.57

ClinPred

0.78

GERP RS

0.57

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Mutation Taster

=0/200

disease causing (ClinVar)

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.18

Details are displayed if max score is > 0.2

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

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over