rs558998633

Variant names:

• chr3-49419764-G-A
• rs558998633
• NM_000481.4:c.496C>T

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_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
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: 0.326
• Publications: 0 publications found

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, Myriad Women’s Health, Labcorp Genetics (formerly Invitae)
• 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

ENSG00000283189 (HGNC:):

ACMG classification

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.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000481.4. 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
	AMT	NM_000481.4	MANE Select	c.496C>T	p.Gln166*	stop_gained	Exon 5 of 9	NP_000472.2
	AMT	NM_001164712.2		c.496C>T	p.Gln166*	stop_gained	Exon 5 of 10	NP_001158184.1	P48728-4
	AMT	NM_001164710.2		c.364C>T	p.Gln122*	stop_gained	Exon 4 of 8	NP_001158182.1	P48728-3

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	AMT	ENST00000273588.9	TSL:1 MANE Select	c.496C>T	p.Gln166*	stop_gained	Exon 5 of 9	ENSP00000273588.3	P48728-1
	ENSG00000283189	ENST00000636166.1	TSL:5	c.733C>T	p.Gln245*	stop_gained	Exon 7 of 11	ENSP00000490106.1	A0A1B0GUH1
	AMT	ENST00000395338.7	TSL:1	c.496C>T	p.Gln166*	stop_gained	Exon 5 of 10	ENSP00000378747.2	P48728-4

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152128 Hom.: 0 Cov.: 32

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.: 31

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152246 Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1 AN XY: 74442

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

African (AFR) AF: 0.00 AC: 0 AN: 41552

American (AMR) AF: 0.00 AC: 0 AN: 15280

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5182

South Asian (SAS) AF: 0.000207 AC: 1 AN: 4828

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10606

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 292

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68016

Other (OTH) AF: 0.00 AC: 0 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.

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ExAC AF: 0.00000824 AC: 1

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
3	-	-	Glycine encephalopathy (3)
1	-	-	Glycine encephalopathy 1 (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.55	D
BayesDel_noAF	Uncertain	0.040
CADD	Pathogenic	32
DANN	Uncertain	0.98
Eigen	Benign	-0.11
Eigen_PC	Benign	-0.39
FATHMM_MKL	Benign	0.062	N
PhyloP100		0.33
Vest4		0.57
ClinPred		0.78	D
GERP RS		0.57
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Mutation Taster		=0/200	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs558998633; hg19: chr3-49457197;