rs121434296

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM2PM5PP3_ModeratePP5

The NM_005957.5(MTHFR):​c.1129C>T​(p.Arg377Cys) variant causes a missense change. The variant allele was found at a frequency of 0.0000235 in 1,614,086 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 13/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R377H) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000023 ( 0 hom. )

Consequence

MTHFR
NM_005957.5 missense

Scores

16
2
1

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:7U:1

Conservation

PhyloP100: 3.90

Publications

12 publications found
Variant links:
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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr1-11794765-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 654511.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.931
PP5
Variant 1-11794766-G-A is Pathogenic according to our data. Variant chr1-11794766-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 3528.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MTHFRNM_005957.5 linkc.1129C>T p.Arg377Cys missense_variant Exon 7 of 12 ENST00000376590.9 NP_005948.3 P42898-1Q8IU67Q59GJ6

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MTHFRENST00000376590.9 linkc.1129C>T p.Arg377Cys missense_variant Exon 7 of 12 1 NM_005957.5 ENSP00000365775.3 P42898-1

Frequencies

GnomAD3 genomes
AF:
0.0000329
AC:
5
AN:
152206
Hom.:
0
Cov.:
33
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:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000735
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000199
AC:
5
AN:
251484
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000440
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000226
AC:
33
AN:
1461880
Hom.:
0
Cov.:
35
AF XY:
0.0000193
AC XY:
14
AN XY:
727240
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.0000252
AC:
1
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86256
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53414
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000279
AC:
31
AN:
1112008
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.486
Heterozygous variant carriers
0
3
5
8
10
13
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000329
AC:
5
AN:
152206
Hom.:
0
Cov.:
33
AF XY:
0.0000269
AC XY:
2
AN XY:
74362
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41458
American (AMR)
AF:
0.00
AC:
0
AN:
15282
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5186
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10616
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000735
AC:
5
AN:
68040
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.495
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0000481
Hom.:
0
Bravo
AF:
0.0000227
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000116
AC:
1
ExAC
AF:
0.0000247
AC:
3
EpiCase
AF:
0.000218
EpiControl
AF:
0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:7Uncertain:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Homocystinuria due to methylene tetrahydrofolate reductase deficiency Pathogenic:4
Jul 23, 2024
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: MTHFR c.1129C>T (p.Arg377Cys) results in a non-conservative amino acid change located in the MTHFR, SAM-binding regulatory domain (IPR053806) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 2e-05 in 251484 control chromosomes (gnomAD). c.1129C>T has been reported in the literature in multiple individuals including homozygotes affected with Homocystinuria Due To Methylene Tetrahydrofolate Reductase Deficiency (examples : Strauss_2007, Gowda_2021, Ghosh_2017). These data indicate that the variant is very likely to be associated with disease. In vitro functional assays show reduced activity for the variant (Burda_2017). The following publications have been ascertained in the context of this evaluation (PMID: 17409006, 34347262, 28468868, 27743313). ClinVar contains an entry for this variant (Variation ID: 3528). Based on the evidence outlined above, the variant was classified as pathogenic. -

Dec 19, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 377 of the MTHFR protein (p.Arg377Cys). This variant is present in population databases (rs121434296, gnomAD 0.004%). This missense change has been observed in individual(s) with clinical features of severe MTHFR deficiency and/or MTHFR deficiency (PMID: 8940272, 12673793, 17409006, 25736335, 26025547, 26872964; Invitae). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. It is commonly reported in individuals of Amish ancestry (PMID: 17409006). This variant is also known as C1141T. ClinVar contains an entry for this variant (Variation ID: 3528). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on MTHFR protein function. Experimental studies are conflicting or provide insufficient evidence to determine the effect of this variant on MTHFR function (PMID: 10551815, 27743313, 34214447). This variant disrupts the p.Arg377 amino acid residue in MTHFR. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 10923034, 26025547). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Jun 01, 2007
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

May 08, 2023
Genomic Medicine Center of Excellence, King Faisal Specialist Hospital and Research Centre
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:research

- -

not provided Pathogenic:2Uncertain:1
Jan 01, 2022
CeGaT Center for Human Genetics Tuebingen
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Feb 06, 2018
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.1129C>T; p.Arg377Cys variant has been reported multiple times in the literature. An African-American/Caucasian female with lethargy and failure to thrive at one month of age, and seizures, apnea, and hypotonia at three months of age was reported to be compound heterozygous for this variant as well as p.Leu323Pro (Goyette 1996). A 13-year-old male with developmental delay was reported to be compound heterozygous for the p.Arg377Cys and p.Met338Thr variants (Sibani 2003), and a study of families diagnosed with severe MTHFR deficiency reported two further individuals heterozygous for p.Arg377Cys and either p.His181Asp or p.Cys193Tyr (Tonetti 2003). A study of an Amish community found four children homozygous for the p.Arg377Cys variant, all of whom had slow head growth and arrested development in the first few months of life; while 68 heterozygotes were among 230 healthy individuals in the community, for an estimated population carrier frequency of 30% (Strauss 2007). The four p.Arg377Cys homozygotes all displayed elevated plasma N-homocysteinylated protein, Hcy-thiolactone and total homocysteine concentrations (Jakubowski 2008). This variant is listed in the genome Aggregation Database (gnomAD) with an overall population frequency of 0.004% (identified on 5 out of 126,714 chromosomes) and an East Asian population frequency of zero (out of 18,870 chromosomes), while the Exome Sequencing Project reports the variant frequency as 0.008% (identified on 1 out of 13,005 chromosomes). However, a study of congenital heart disease risk in China identified the p.Arg377Cys variant in a homozygous state in 12 healthy individuals and 27 affected patients among 467 studied Chinese Han individuals, with an allele frequency of over 25% (Zhang 2014). The discrepancy between this report and those of the population databases has not yet been explained. Although these findings are suggestive, based on the available evidence, the clinical significance of the p.Arg377Cys variant cannot be determined with certainty. -

Dec 16, 2024
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Also known as c.1141C>T; This variant is associated with the following publications: (PMID: 25855017, 25736335, 10923034, 17327360, 10551815, 8940272, 31980526, 23183749, 17409006, 12673793, 26872964, 18708589, 22594747, 34426522, 28468868, 34214447, 27743313, 20356773, 35008593, 26025547, 24797679, 33089527, 20394947, 34347262, 24720776) -

Neural tube defects, folate-sensitive Pathogenic:1
Feb 28, 2024
Baylor Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.70
BayesDel_addAF
Pathogenic
0.31
D
BayesDel_noAF
Pathogenic
0.31
CADD
Pathogenic
34
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.87
D;.;.;D;.;.;.
Eigen
Pathogenic
0.81
Eigen_PC
Pathogenic
0.72
FATHMM_MKL
Uncertain
0.89
D
LIST_S2
Pathogenic
0.99
.;D;.;D;D;D;D
M_CAP
Pathogenic
0.32
D
MetaRNN
Pathogenic
0.93
D;D;D;D;D;D;D
MetaSVM
Uncertain
0.64
D
MutationAssessor
Pathogenic
4.0
H;.;.;H;.;.;.
PhyloP100
3.9
PrimateAI
Pathogenic
0.83
D
PROVEAN
Pathogenic
-7.9
D;D;D;D;.;.;.
REVEL
Pathogenic
0.85
Sift
Pathogenic
0.0
D;D;D;D;.;.;.
Sift4G
Pathogenic
0.0
D;D;D;D;.;.;.
Polyphen
1.0
D;.;.;D;.;.;.
Vest4
0.95
MVP
0.89
MPC
1.1
ClinPred
1.0
D
GERP RS
4.9
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.8
Varity_R
0.93
gMVP
0.95
Mutation Taster
=0/100
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.020
Details are displayed if max score is > 0.2

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

Publications

Other links and lift over

dbSNP: rs121434296; hg19: chr1-11854823; COSMIC: COSV64877526; COSMIC: COSV64877526; API