2-74198696-C-A

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_006636.4(MTHFD2):c.55C>A(p.His19Asn) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,459,154 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. H19Y) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: MTHFD2 NM_006636.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.38

Genes affected

MTHFD2 (HGNC:7434): (methylenetetrahydrofolate dehydrogenase (NADP+ dependent) 2, methenyltetrahydrofolate cyclohydrolase) This gene encodes a nuclear-encoded mitochondrial bifunctional enzyme with methylenetetrahydrofolate dehydrogenase and methenyltetrahydrofolate cyclohydrolase activities. The enzyme functions as a homodimer and is unique in its absolute requirement for magnesium and inorganic phosphate. Formation of the enzyme-magnesium complex allows binding of NAD. Alternative splicing results in two different transcripts, one protein-coding and the other not protein-coding. This gene has a pseudogene on chromosome 7. [provided by RefSeq, Mar 2009]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.10445869).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MTHFD2	NM_006636.4	c.55C>A	p.His19Asn	missense_variant	1/8	ENST00000394053.7
MTHFD2	NM_001410192.1	c.-350C>A		5_prime_UTR_variant	1/9
MTHFD2	XM_006711924.3	c.-67C>A		5_prime_UTR_variant	1/7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MTHFD2	ENST00000394053.7	c.55C>A	p.His19Asn	missense_variant	1/8	1	NM_006636.4	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1459154 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 726000

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: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jul 30, 2023

The c.55C>A (p.H19N) alteration is located in exon 1 (coding exon 1) of the MTHFD2 gene. This alteration results from a C to A substitution at nucleotide position 55, causing the histidine (H) at amino acid position 19 to be replaced by an asparagine (N). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.095
BayesDel_addAF	Benign	-0.18	T
BayesDel_noAF	Benign	-0.50
Cadd	Benign	18
Dann	Benign	0.71
DEOGEN2	Benign	0.22	T;T;T
Eigen	Benign	-0.59
Eigen_PC	Benign	-0.50
FATHMM_MKL	Uncertain	0.77	D
LIST_S2	Benign	0.74	T;T;T
M_CAP	Benign	0.018	T
MetaRNN	Benign	0.10	T;T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	0.55	N;.;.
MutationTaster	Benign	1.0	D;D;N;N;N
PrimateAI	Benign	0.42	T
PROVEAN	Benign	-0.74	N;N;N
REVEL	Benign	0.073
Sift	Benign	0.17	T;D;T
Sift4G	Benign	0.32	T;T;T
Polyphen		0.0010	B;.;B
Vest4		0.20
MutPred		0.37		Gain of relative solvent accessibility (P = 0.0166);Gain of relative solvent accessibility (P = 0.0166);Gain of relative solvent accessibility (P = 0.0166);
MVP		0.39
MPC		0.16
ClinPred		0.26	T
GERP RS		4.6
Varity_R		0.18
gMVP		0.46

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: rs780000573; hg19: chr2-74425823;