1-236835586-G-A

Variant names:

• chr1-236835586-G-A
• rs121913582
• NM_000254.3:c.1228G>A

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM2 PM5 PP3_Strong

The NM_000254.3(MTR):​c.1228G>A​(p.Ala410Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,872 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A410P) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: MTR NM_000254.3 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 9.30
• Publications: 0 publications found

Genes affected

MTR (HGNC:7468): (5-methyltetrahydrofolate-homocysteine methyltransferase) This gene encodes the 5-methyltetrahydrofolate-homocysteine methyltransferase. This enzyme, also known as cobalamin-dependent methionine synthase, catalyzes the final step in methionine biosynthesis. Mutations in MTR have been identified as the underlying cause of methylcobalamin deficiency complementation group G. Alternatively spliced transcript variants encoding distinct isoforms have been found for this gene. [provided by RefSeq, May 2014]

MTR Gene-Disease associations (from GenCC):

• methylcobalamin deficiency type cblG

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), ClinGen, G2P

ACMG classification

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr1-236835586-G-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 14288.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.988

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000254.3. 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
	MTR	NM_000254.3	MANE Select	c.1228G>A	p.Ala410Thr	missense	Exon 14 of 33	NP_000245.2	Q99707-1
	MTR	NM_001291939.1		c.1228G>A	p.Ala410Thr	missense	Exon 14 of 32	NP_001278868.1	Q99707-2
	MTR	NM_001410942.1		c.1228G>A	p.Ala410Thr	missense	Exon 14 of 31	NP_001397871.1	A0A7P0TAJ0

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MTR	ENST00000366577.10	TSL:1 MANE Select	c.1228G>A	p.Ala410Thr	missense	Exon 14 of 33	ENSP00000355536.5	Q99707-1
	MTR	ENST00000535889.6	TSL:1	c.1228G>A	p.Ala410Thr	missense	Exon 14 of 32	ENSP00000441845.1	Q99707-2
	MTR	ENST00000681102.1		c.1228G>A	p.Ala410Thr	missense	Exon 14 of 32	ENSP00000505600.1	A0A7P0T9G7

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461872 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727238

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.0000224 AC: 1 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86254

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1112000

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome Cov.: 31

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.78
BayesDel_addAF	Pathogenic	0.54	D
BayesDel_noAF	Pathogenic	0.54
CADD	Pathogenic	29
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.85	D
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Pathogenic	1.0	D
M_CAP	Pathogenic	0.62	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.5	H
PhyloP100		9.3
PrimateAI	Uncertain	0.53	T
PROVEAN	Uncertain	-3.7	D
REVEL	Pathogenic	0.96
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.80
MutPred		0.93		Loss of helix (P = 0.1299)
MVP		0.97
MPC		1.2
ClinPred		1.0	D
GERP RS		5.8
PromoterAI		-0.023	Neutral
RBP_binding_hub_radar		1.1
RBP_regulation_power_radar		2.8
Varity_R		0.92
gMVP		0.90
Mutation Taster		=25/75	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs121913582; hg19: chr1-236998886;