1-11796321-G-T

Variant names:

• chr1-11796321-G-T
• rs1801133
• NM_005957.5:c.665C>A

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM1 PM2 PP3_Strong

The NM_005957.5(MTHFR):​c.665C>A​(p.Ala222Asp) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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. A222V) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: MTHFR NM_005957.5 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 9.14
• Publications: 1 publications found

Genes affected

MTHFR (HGNC:7436): (methylenetetrahydrofolate reductase) The protein encoded by this gene catalyzes the conversion of 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate, a co-substrate for homocysteine remethylation to methionine. Genetic variation in this gene influences susceptibility to occlusive vascular disease, neural tube defects, colon cancer and acute leukemia, and mutations in this gene are associated with methylenetetrahydrofolate reductase deficiency.[provided by RefSeq, Oct 2009]

MTHFR Gene-Disease associations (from GenCC):

• homocystinuria due to methylene tetrahydrofolate reductase deficiency

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

ACMG classification

Our verdict: Likely_pathogenic. The variant received 8 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, 4 uncertain in NM_005957.5
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.941

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MTHFR	NM_005957.5	c.665C>A	p.Ala222Asp	missense_variant	Exon 5 of 12	ENST00000376590.9	NP_005948.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MTHFR	ENST00000376590.9	c.665C>A	p.Ala222Asp	missense_variant	Exon 5 of 12	1	NM_005957.5	ENSP00000365775.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 40

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.59
CADD	Pathogenic	29
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.98	D;.;.;D;.;.;.
Eigen	Pathogenic	0.94
Eigen_PC	Pathogenic	0.79
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.96	.;D;.;D;D;D;D
M_CAP	Pathogenic	0.44	D
MetaRNN	Pathogenic	0.94	D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.9	H;.;.;H;.;.;.
PhyloP100		9.1
PrimateAI	Uncertain	0.69	T
PROVEAN	Pathogenic	-5.0	D;D;D;D;.;.;.
REVEL	Pathogenic	0.92
Sift	Uncertain	0.0010	D;D;D;D;.;.;.
Sift4G	Uncertain	0.0030	D;D;D;D;.;.;.
Polyphen		1.0	D;.;.;D;.;.;.
Vest4		0.97
MutPred		0.68		Loss of catalytic residue at A222 (P = 0.0165);.;.;Loss of catalytic residue at A222 (P = 0.0165);.;Loss of catalytic residue at A222 (P = 0.0165);Loss of catalytic residue at A222 (P = 0.0165);
MVP		1.0
MPC		1.2
ClinPred		1.0	D
GERP RS		5.1
PromoterAI		0.034	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.99
gMVP		0.99
Mutation Taster		=14/86	disease causing

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: rs1801133; hg19: chr1-11856378;