15-79845257-C-T

Variant names:

• chr15-79845257-C-T
• rs964704236
• NM_006441.4:c.565G>A

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1 PM2 PP3_Strong

The NM_006441.4(MTHFS):​c.565G>A​(p.Asp189Asn) variant causes a missense change. The variant allele was found at a frequency of 0.00000342 in 1,461,888 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: MTHFS NM_006441.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.19

Genes affected

MTHFS (HGNC:7437): (methenyltetrahydrofolate synthetase) The protein encoded by this gene is an enzyme that catalyzes the conversion of 5-formyltetrahydrofolate to 5,10-methenyltetrahydrofolate, a precursor of reduced folates involved in 1-carbon metabolism. An increased activity of the encoded protein can result in an increased folate turnover rate and folate depletion. Three transcript variants encoding two different isoforms have been found for this gene. [provided by RefSeq, Jun 2011]

ST20-MTHFS (HGNC:44655): (ST20-MTHFS readthrough) This locus represents naturally occurring read-through transcription between the neighboring suppressor of tumorigenicity 20 and 5,10-methenyltetrahydrofolate synthetase (5-formyltetrahydrofolate cyclo-ligase) genes on chromosome 15. The read-through transcript produces a fusion protein that shares sequence identity with each individual gene product. [provided by RefSeq, Dec 2010]

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PM1: In a binding_site (size 0) in uniprot entity MTHFS_HUMAN
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.989

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MTHFS	NM_006441.4	c.565G>A	p.Asp189Asn	missense_variant	Exon 3 of 3	ENST00000258874.4	NP_006432.1
ST20-MTHFS	NM_001199760.2	c.493G>A	p.Asp165Asn	missense_variant	Exon 4 of 4		NP_001186689.1
MTHFS	NM_001199758.1	c.394G>A	p.Asp132Asn	missense_variant	Exon 3 of 3		NP_001186687.1
MTHFS	NR_037654.2	n.672G>A		non_coding_transcript_exon_variant	Exon 3 of 3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MTHFS	ENST00000258874.4	c.565G>A	p.Asp189Asn	missense_variant	Exon 3 of 3	1	NM_006441.4	ENSP00000258874.4
ST20-MTHFS	ENST00000479961.1	c.493G>A	p.Asp165Asn	missense_variant	Exon 4 of 4	3		ENSP00000455643.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251418 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135874

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 SAS exome AF: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461888 Hom.: 0 Cov.: 31 AF XY: 0.00000413 AC XY: 3 AN XY: 727244

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000232

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000712 Hom.: 0

Bravo AF: 0.0000151

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

May 22, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces aspartic acid, which is acidic and polar, with asparagine, which is neutral and polar, at codon 189 of the MTHFS protein (p.Asp189Asn). This variant is present in population databases (no rsID available, gnomAD 0.003%). This variant has not been reported in the literature in individuals affected with MTHFS-related conditions. ClinVar contains an entry for this variant (Variation ID: 1974883). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. 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
AlphaMissense	Pathogenic	0.94
BayesDel_addAF	Pathogenic	0.18	D
BayesDel_noAF	Uncertain	0.12
CADD	Pathogenic	29
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.66	D;.;.;.
Eigen	Pathogenic	0.89
Eigen_PC	Pathogenic	0.81
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.94	D;D;.;D
M_CAP	Pathogenic	0.31	D
MetaRNN	Pathogenic	0.99	D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.0	H;.;.;.
PrimateAI	Uncertain	0.54	T
PROVEAN	Pathogenic	-4.4	D;.;.;D
REVEL	Pathogenic	0.72
Sift	Pathogenic	0.0	D;.;.;D
Sift4G	Uncertain	0.047	D;D;D;D
Polyphen		0.99	D;.;.;.
Vest4		0.98
MutPred		0.93		Gain of methylation at K191 (P = 0.1018);.;.;.;
MVP		0.98
MPC		0.87
ClinPred		1.0	D
GERP RS		6.0
Varity_R		0.93
gMVP		0.86

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

Publications

LitVar

Other links and lift over

dbSNP: rs964704236; hg19: chr15-80137599;