1-241504227-G-C

Position:

chr1-241504227-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 7P and 4B. PM1PM5PP3_ModeratePP5BS2

The NM_000143.4(FH):c.923C>G(p.Ala308Gly) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000204 in 1,614,004 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. A308T) has been classified as Pathogenic.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000021 ( 0 hom. )

Consequence

FH
NM_000143.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:4U:2

Conservation

PhyloP100: 7.53

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:

FH (HGNC:):

FH links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 3 ACMG points.

PM1

In a hotspot region, there are 6 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 11 uncertain in NM_000143.4

PM5

Other missense variant is known to change same aminoacid residue: Variant chr1-241504228-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 1324397.Status of the report is criteria_provided_single_submitter, 1 stars.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.932

PP5

Variant 1-241504227-G-C is Pathogenic according to our data. Variant chr1-241504227-G-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 392178.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=2, Pathogenic=1, Likely_pathogenic=3}.

BS2

High AC in GnomAdExome4 at 31 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
FH	NM_000143.4 linkuse as main transcript	c.923C>G	p.Ala308Gly	missense_variant	7/10	ENST00000366560.4	NP_000134.2	P07954-1A0A0S2Z4C3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
FH	ENST00000366560.4 linkuse as main transcript	c.923C>G	p.Ala308Gly	missense_variant	7/10	1	NM_000143.4	ENSP00000355518.4		P07954-1

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152184

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:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000398

AC:

AN:

251026

Hom.:

AF XY:

0.00

AC XY:

AN XY:

135670

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:

0.00000882

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000212

AC:

AN:

1461820

Hom.:

Cov.:

AF XY:

0.0000179

AC XY:

AN XY:

727216

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:

0.0000279

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152184

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74332

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:

0.0000294

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000113

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:4Uncertain:2

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Dec 29, 2023	This sequence change replaces alanine, which is neutral and non-polar, with glycine, which is neutral and non-polar, at codon 308 of the FH protein (p.Ala308Gly). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with fumarate hydratase deficiency (Invitae). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 392178). 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%. RNA analysis performed to evaluate the impact of this missense change on mRNA splicing indicates it does not significantly alter splicing (Invitae). This variant disrupts the p.Ala308 amino acid residue in FH. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 9635293, 29456767). 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. -
Likely pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Mar 11, 2022	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; Observed in individuals with no reported personal history of early onset renal cell cancer undergoing multi-gene hereditary cancer panel testing in published literature (Kamihara 2021); While this variant is considered likely pathogenic for autosomal recessive fumarate hydratase deficiency, heterozygous carriers have not been reported to have hereditary leiomyomatosis and renal cell cancer (HLRCC), therefore its association with HLRCC is uncertain (Kamihara 2021); Also known as A265G; This variant is associated with the following publications: (PMID: 34994643, 9635293) -
Likely pathogenic, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Jul 01, 2023	FH: PM2, PM3, PM5, PP3 -

Fumarase deficiency

Pathogenic:1Uncertain:1

Uncertain significance, criteria provided, single submitter	clinical testing	Baylor Genetics	Feb 06, 2024	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Victorian Clinical Genetics Services, Murdoch Childrens Research Institute	Feb 02, 2022	Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as Likely pathogenic. Following criteria are met: 0102 - Loss of function is a known mechanism of disease in this gene and is associated with fumarase deficiency (MIM#606812) and leiomyomatosis and renal cell cancer (MIM#150800). (I) 0108 - This gene is associated with both recessive and dominant disease (OMIM). (I) 0200 - Variant is predicted to result in a missense amino acid change from alanine to glycine. (I) 0251 - This variant is heterozygous. (I) 0304 - Variant is present in gnomAD (v3) <0.01 for a recessive condition (2 heterozygotes, 0 homozygotes). (SP) 0501 - Missense variant consistently predicted to be damaging by multiple in silico tools or highly conserved with a major amino acid change. (SP) 0600 - Variant is located in the annotated Lyase domain (Decipher). (I) 0704 - Another missense variant comparable to the one identified in this case has limited previous evidence for pathogenicity. The alternative change to a threonine has been reported in one homozygous individual with fumarase deficiency (PMID: 9635293). (SP) 0802 - This variant has moderate previous evidence of pathogenicity in unrelated individuals. This variant has been reported multiple times in individuals with fumarase deficiency (ClinVar). (SP) 0905 - No published segregation evidence has been identified for this variant. (I) 1007 - No published functional evidence has been identified for this variant. (I) 1208 - Inheritance information for this variant is not currently available in this individual. (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -

Hereditary cancer-predisposing syndrome

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 05, 2024

The p.A308G variant (also known as c.923C>G), located in coding exon 7 of the FH gene, results from a C to G substitution at nucleotide position 923. The alanine at codon 308 is replaced by glycine, an amino acid with similar properties. This alteration has been observed in individuals who do not have a personal or family history that is consistent with or suggestive of FH-associate HLRCC (Ambry internal data). However, this alteration has been identified in trans with another FH pathogenic alteration in an individual with autosomal recessive fumarate hydratase deficiency syndrome (personal communication). Another alteration at this same amino acid position, p.A308T (also designated as p.A265T in published literature), has also been reported in a homozygous state in a patient with fumarate hydratase deficiency (Coughlin EM et al. Mol. Genet. Metab., 1998 Apr;63:254-62) and follow-up studies showed that it is catalytically inactive and unable to form multimers in functional assays using recombinant proteins (Bulku A et al. Open Biochem J, 2018 Jan;12:1-15). This amino acid position is highly conserved in available vertebrate species. In addition, p.A308G is predicted to be deleterious by in silico analysis. Based on the majority of available evidence to date, this variant is expected to be causative of autosomal recessive fumarate hydratase deficiency when present along with a second likely pathogenic/pathogenic variant on the other allele; however, the significance for autosomal dominant HLRCC is unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.56

BayesDel_addAF

Pathogenic

0.50

BayesDel_noAF

Pathogenic

0.48

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.98

Eigen

Pathogenic

0.98

Eigen_PC

Pathogenic

0.94

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Pathogenic

0.98

M_CAP

Pathogenic

0.77

MetaRNN

Pathogenic

0.93

MetaSVM

Pathogenic

1.0

MutationAssessor

Pathogenic

3.6

PrimateAI

Uncertain

0.72

PROVEAN

Uncertain

-3.6

REVEL

Pathogenic

0.95

Sift

Uncertain

0.0010

Sift4G

Uncertain

0.0020

Polyphen

0.91

Vest4

0.77

MutPred

0.71

Gain of catalytic residue at P304 (P = 0.0924);

MVP

0.97

MPC

0.95

ClinPred

0.99

GERP RS

5.7

Varity_R

0.96

gMVP

0.91

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