1-241506090-C-T

Variant names:

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1PM2PP3_Moderate

The NM_000143.4(FH):c.817G>A(p.Ala273Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000031 in 1,613,840 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A273V) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000027 ( 0 hom. )

Consequence

FH
NM_000143.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:5

Conservation

PhyloP100: 7.37

Variant links:

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]

FH links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

PM1

In a hotspot region, there are 7 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 11 uncertain in NM_000143.4

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.928

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FH	NM_000143.4 link	c.817G>A	p.Ala273Thr	missense_variant	Exon 6 of 10	ENST00000366560.4	NP_000134.2	P07954-1A0A0S2Z4C3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
FH	ENST00000366560.4 link	c.817G>A	p.Ala273Thr	missense_variant	Exon 6 of 10	1	NM_000143.4	ENSP00000355518.4		P07954-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152162

Hom.:

Cov.:

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000398

AC:

AN:

251224

Hom.:

AF XY:

0.00000737

AC XY:

AN XY:

135762

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 SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000880

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000274

AC:

AN:

1461678

Hom.:

Cov.:

AF XY:

0.00000275

AC XY:

AN XY:

727148

show subpopulations

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:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000180

Gnomad4 OTH exome

AF:

0.0000331

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152162

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74344

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000756

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1Uncertain:5

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Pathogenic:1Uncertain:1

Apr 18, 2023

GeneDx

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Observed in individuals with paraganglioma, including one apparently de novo observation (Ben Aim et al., 2019; Ma et al., 2020; Snabboon et al., 2020); Not observed at significant frequency in large population cohorts (gnomAD); Also known as p.A230T; This variant is associated with the following publications: (PMID: 32612247, 30548923, 33125697, 30877234, 33362715, 34750850, 35821608, 36773955) -

Nov 10, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 273 of the FH protein (p.Ala273Thr). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with paraganglioma (PMID: 30877234, 33125697, 33362715, 34750850, 35821608). ClinVar contains an entry for this variant (Variation ID: 214377). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt FH protein function with a positive predictive value of 95%. 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. -

Hereditary cancer-predisposing syndrome

Uncertain:2

Sep 09, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.A273T variant (also known as c.817G>A), located in coding exon 6 of the FH gene, results from a G to A substitution at nucleotide position 817. The alanine at codon 273 is replaced by threonine, an amino acid with similar properties. This variant was reported in multiple individuals with a personal and/or family history of pheochromocytoma and/or paraganglioma (Snabboon T et al. Endokrynol Pol, 2020 Oct;71:583-584; Ma X et al. Ann N Y Acad Sci, 2022 Oct;1516:262-270; Parisien-La Salle S et al. Clin Endocrinol (Oxf), 2022 Jun;96:803-811). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, the clinical significance of this variant remains unclear. -

Jun 21, 2021

Sema4, Sema4

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: curation

- -

not specified

Uncertain:1

Sep 14, 2023

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: FH c.817G>A (p.Ala273Thr) results in a non-conservative amino acid change located in the Fumarate lyase, N-terminal (IPR022761) 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 4e-06 in 251224 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.817G>A has been reported in the literature in individuals affected with paraganglioma, including a de novo occurrence (Snabboon_2020, Ma_2020, Parisien-LaSalle_2022). These reports do not provide unequivocal conclusions about association of the variant with Hereditary Leiomyomatosis And Renal Cell Cancer. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 33125697, 33362715, 34750850). Five submitters have cited clinical-significance assessments for this variant to ClinVar after 2014, and classified it as uncertain significance (n=4) or likely pathogenic (n=1). Based on the evidence outlined above, the variant was classified as uncertain significance. -

Fumarase deficiency

Uncertain:1

Aug 30, 2021

Natera, Inc.

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.91

BayesDel_addAF

Pathogenic

0.52

BayesDel_noAF

Pathogenic

0.50

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.98

Eigen

Pathogenic

0.95

Eigen_PC

Pathogenic

0.87

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.90

M_CAP

Pathogenic

0.76

MetaRNN

Pathogenic

0.93

MetaSVM

Pathogenic

1.0

MutationAssessor

Pathogenic

3.6

PrimateAI

Uncertain

0.70

PROVEAN

Uncertain

-3.9

REVEL

Pathogenic

0.87

Sift

Pathogenic

0.0

Sift4G

Pathogenic

0.0

Polyphen

1.0

Vest4

0.90

MutPred

0.48

Loss of MoRF binding (P = 0.1318);

MVP

0.97

MPC

0.96

ClinPred

1.0

GERP RS

5.6

Varity_R

0.93

gMVP

0.88

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over