rs755436052

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM1PP2PP3_StrongPP5

The NM_000143.4(FH):​c.1048C>T​(p.Arg350Trp) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000013 in 1,614,048 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 13/22 in silico tools predict a damaging 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. R350Q) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000012 ( 0 hom. )

Consequence

FH
NM_000143.4 missense

Scores

17
1

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:6U:6

Conservation

PhyloP100: 7.37

Publications

3 publications found
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 Gene-Disease associations (from GenCC):
  • hereditary leiomyomatosis and renal cell cancer
    Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: ClinGen, Ambry Genetics, G2P, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Orphanet
  • fumaric aciduria
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Orphanet, Labcorp Genetics (formerly Invitae), Ambry Genetics
  • pheochromocytoma-paraganglioma
    Inheritance: AD Classification: STRONG Submitted by: Ambry Genetics
  • leiomyosarcoma
    Inheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
  • hereditary pheochromocytoma-paraganglioma
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

PM1
In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 25 uncertain in NM_000143.4
PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 132 curated pathogenic missense variants (we use a threshold of 10). The gene has 17 curated benign missense variants. Gene score misZ: 1.2708 (below the threshold of 3.09). Trascript score misZ: 2.0634 (below the threshold of 3.09). GenCC associations: The gene is linked to fumaric aciduria, hereditary leiomyomatosis and renal cell cancer, hereditary pheochromocytoma-paraganglioma, leiomyosarcoma, pheochromocytoma-paraganglioma.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.939
PP5
Variant 1-241504102-G-A is Pathogenic according to our data. Variant chr1-241504102-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 214418.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
FHNM_000143.4 linkc.1048C>T p.Arg350Trp missense_variant Exon 7 of 10 ENST00000366560.4 NP_000134.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
FHENST00000366560.4 linkc.1048C>T p.Arg350Trp missense_variant Exon 7 of 10 1 NM_000143.4 ENSP00000355518.4

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152174
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000241
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
GnomAD2 exomes
AF:
0.0000159
AC:
4
AN:
251258
AF XY:
0.0000147
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 FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000176
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000123
AC:
18
AN:
1461874
Hom.:
0
Cov.:
33
AF XY:
0.0000124
AC XY:
9
AN XY:
727238
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44716
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.0000252
AC:
1
AN:
39696
South Asian (SAS)
AF:
0.0000464
AC:
4
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000108
AC:
12
AN:
1112004
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.464
Heterozygous variant carriers
0
1
2
4
5
6
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000197
AC:
3
AN:
152174
Hom.:
0
Cov.:
32
AF XY:
0.0000269
AC XY:
2
AN XY:
74330
show subpopulations
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.0000241
AC:
1
AN:
41448
American (AMR)
AF:
0.00
AC:
0
AN:
15284
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5194
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10600
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68026
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.0000000000000565104), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.325
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0000113
Hom.:
0
Bravo
AF:
0.0000227
ExAC
AF:
0.0000247
AC:
3
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:6Uncertain:6
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Fumarase deficiency Pathogenic:3Uncertain:2
Apr 27, 2017
Illumina Laboratory Services, Illumina
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance.

Jan 25, 2024
Baylor Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Dec 02, 2020
Institute of Human Genetics Munich, TUM University Hospital
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Jun 08, 2023
3billion
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The variant is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: 0.002%). Predicted Consequence/Location: Missense variant In silico tool predictions suggest damaging effect of the variant on gene or gene product (REVEL: 0.86; 3Cnet: 0.91). Same nucleotide change resulting in same amino acid change has been previously reported to be associated with FH related disorder (PMID: 34643235). However, the evidence of pathogenicity is insufficient at this time. Therefore, this variant is classified as VUS according to the recommendation of ACMG/AMP guideline.

Jun 12, 2024
Department of Genetics, Sultan Qaboos University Hospital
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:curation

not provided Pathogenic:3Uncertain:1
Dec 26, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 350 of the FH protein (p.Arg350Trp). This variant is present in population databases (rs755436052, gnomAD 0.006%). This missense change has been observed in individual(s) with autosomal recessive fumarate hydratase deficiency (PMID: 34643235). ClinVar contains an entry for this variant (Variation ID: 214418). 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%. For these reasons, this variant has been classified as Pathogenic.

Jun 01, 2025
CeGaT Center for Human Genetics Tuebingen
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

FH: PM2, PS4:Moderate, PP3, PS3:Supporting

Nov 03, 2021
Institute for Clinical Genetics, University Hospital TU Dresden, University Hospital TU Dresden
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Mar 18, 2025
GeneDx
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Published functional studies suggest a reduction in enzyme activity for fumarate and malate conversion in vitro (PMID: 37255402); 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; This variant is associated with the following publications: (PMID: 34643235, 36211164, 37255402, Larouche2024[abstract])

not specified Uncertain:1
Mar 04, 2025
Center for Genomic Medicine, Rigshospitalet, Copenhagen University Hospital
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Fumarase deficiency;C1708350:Hereditary leiomyomatosis and renal cell cancer Uncertain:1
Aug 10, 2022
Department of Pathology and Laboratory Medicine, Sinai Health System
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:research

Hereditary cancer-predisposing syndrome Uncertain:1
Mar 04, 2025
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.R350W variant (also known as c.1048C>T), located in coding exon 7 of the FH gene, results from a C to T substitution at nucleotide position 1048. The arginine at codon 350 is replaced by tryptophan, an amino acid with dissimilar properties. This alteration was found in a homozygous state in a proband meeting clinical criteria for FH deficiency (Jasinge E et al. Lab Med, 2022 May;53:e48-e50). 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 alteration remains unclear.

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.98
BayesDel_addAF
Pathogenic
0.42
D
BayesDel_noAF
Pathogenic
0.55
CADD
Pathogenic
33
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.99
D
Eigen
Pathogenic
0.99
Eigen_PC
Pathogenic
0.86
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Uncertain
0.97
D
M_CAP
Pathogenic
0.48
D
MetaRNN
Pathogenic
0.94
D
MetaSVM
Pathogenic
1.0
D
MutationAssessor
Pathogenic
4.9
H
PhyloP100
7.4
PrimateAI
Pathogenic
0.90
D
PROVEAN
Pathogenic
-7.9
D
REVEL
Pathogenic
0.86
Sift
Pathogenic
0.0
D
Sift4G
Pathogenic
0.0
D
Vest4
0.94
ClinPred
1.0
D
GERP RS
4.8
Varity_R
0.98
gMVP
0.96
Mutation Taster
=8/92
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.020
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs755436052; hg19: chr1-241667402; COSMIC: COSV104677035; API