rs386833691

Variant names:

• chr3-49417878-ACAT-A
• rs386833691
• NM_000481.4:c.970_972delATG

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM1 PM2 PM4_Supporting

The NM_000481.4(AMT):​c.970_972delATG​(p.Met324del) variant causes a conservative inframe deletion change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: AMT NM_000481.4 conservative_inframe_deletion
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts P:1 U:2
• Conservation: PhyloP100: 1.70
• 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, 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

ENSG00000283189 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 6 uncertain in NM_000481.4
• PM2: Very rare variant in population databases, with high coverage
• PM4: Nonframeshift variant in NON repetitive region in NM_000481.4. Strenght limited to Supporting due to length of the change: 1aa.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
AMT	NM_000481.4	c.970_972delATG	p.Met324del	conservative_inframe_deletion	Exon 8 of 9	ENST00000273588.9	NP_000472.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
AMT	ENST00000273588.9	c.970_972delATG	p.Met324del	conservative_inframe_deletion	Exon 8 of 9	1	NM_000481.4	ENSP00000273588.3
ENSG00000283189	ENST00000636166.1	c.1207_1209delATG	p.Met403del	conservative_inframe_deletion	Exon 10 of 11	5		ENSP00000490106.1

Frequencies

GnomAD3 genomes Cov.: 32

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:1 Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Glycine encephalopathy Pathogenic:1 Uncertain:2

-

Juha Muilu Group; Institute for Molecular Medicine Finland (FIMM)

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

May 22, 2022

3billion

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The variant is not observed in the gnomAD v2.1.1 dataset. Inframe deletion located in a nonrepeat region: predicted to change the length of the protein and disrupt normal protein function. The variant has been reported to be associated with AMT related disorder (ClinVar ID: VCV000056240). However, the evidence of pathogenicity is insufficient at this time. Therefore, this variant is classified as uncertain significanceaccording to the recommendation of ACMG/AMP guideline. -

Mar 11, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant, c.970_972del, results in the deletion of 1 amino acid(s) of the AMT protein (p.Met324del), but otherwise preserves the integrity of the reading frame. This variant is not present in population databases (gnomAD no frequency). This variant has been observed in individual(s) with glycine encephalopathy (PMID: 16450403). ClinVar contains an entry for this variant (Variation ID: 56240). Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		1.7
Mutation Taster		=58/42	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs386833691; hg19: chr3-49455311;