rs200004220

Positions:

• chr1-241500572-A-C
• chr1-241500572-A-G
• chr1-241500572-A-T

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM2 PP3_Moderate PP5

The NM_000143.4(FH):​c.1255T>G​(p.Ser419Ala) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency: Genomes: not found (cov: 31)
• Consequence: FH NM_000143.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 7.00

Genes affected

FH (HGNC:3700): (fumarate hydratase) The protein encoded by this gene is an enzymatic component of the tricarboxylic acid (TCA) cycle, or Krebs cycle, and catalyzes the formation of L-malate from fumarate. It exists in both a cytosolic form and an N-terminal extended form, differing only in the translation start site used. The N-terminal extended form is targeted to the mitochondrion, where the removal of the extension generates the same form as in the cytoplasm. It is similar to some thermostable class II fumarases and functions as a homotetramer. Mutations in this gene can cause fumarase deficiency and lead to progressive encephalopathy. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.875
• PP5: Variant 1-241500572-A-C is Pathogenic according to our data. Variant chr1-241500572-A-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 2805452.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
FH	NM_000143.4	c.1255T>G	p.Ser419Ala	missense_variant	9/10	ENST00000366560.4	NP_000134.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
FH	ENST00000366560.4	c.1255T>G	p.Ser419Ala	missense_variant	9/10	1	NM_000143.4	ENSP00000355518	P1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 31

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 20, 2023

This sequence change replaces serine, which is neutral and polar, with alanine, which is neutral and non-polar, at codon 419 of the FH protein (p.Ser419Ala). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with FH-related conditions. 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) performed at Invitae indicates that this missense variant is expected to disrupt FH protein function with a positive predictive value of 95%. This variant disrupts the p.Ser419 amino acid residue in FH. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 15937070, 16597677). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Oct 13, 2023

The p.S419A variant (also known as c.1255T>G), located in coding exon 9 of the FH gene, results from a T to G substitution at nucleotide position 1255. The serine at codon 419 is replaced by alanine, an amino acid with similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.40
BayesDel_addAF	Pathogenic	0.39	D
BayesDel_noAF	Pathogenic	0.32
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.80	D
Eigen	Pathogenic	0.93
Eigen_PC	Pathogenic	0.86
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Pathogenic	0.97	D
M_CAP	Pathogenic	0.43	D
MetaRNN	Pathogenic	0.87	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.4	M
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.71	T
PROVEAN	Uncertain	-3.0	D
REVEL	Pathogenic	0.82
Sift	Pathogenic	0.0	D
Sift4G	Uncertain	0.0090	D
Polyphen		1.0	D
Vest4		0.67
MutPred		0.37		Loss of methylation at K414 (P = 0.1092);
MVP		0.98
MPC		0.89
ClinPred		1.0	D
GERP RS		5.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.73
gMVP		0.95

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr1-241663872;