rs1553341945

Variant names:

• chr1-241517211-T-TA
• rs1553341945
• NM_000143.4:c.237dupT

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000143.4(FH):​c.237dupT​(p.Lys80fs) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. F79F) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: FH NM_000143.4 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 0.329
• Publications: 1 publications found

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

ACMG classification

Our verdict: Pathogenic. The variant received 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 1-241517211-T-TA is Pathogenic according to our data. Variant chr1-241517211-T-TA is described in ClinVar as Pathogenic. ClinVar VariationId is 480830.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FH	NM_000143.4	c.237dupT	p.Lys80fs	frameshift_variant	Exon 2 of 10	ENST00000366560.4	NP_000134.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
FH	ENST00000366560.4	c.237dupT	p.Lys80fs	frameshift_variant	Exon 2 of 10	1	NM_000143.4	ENSP00000355518.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary cancer-predisposing syndrome Pathogenic:2

Dec 14, 2023

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.237dupT pathogenic mutation, located in coding exon 2 of the FH gene, results from a duplication of T at nucleotide position 237, causing a translational frameshift with a predicted alternate stop codon (p.K80*). This alteration has been observed in at least one individual with a personal and/or family history that is consistent with FH-related disease (Ambry internal data). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). This alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. As such, this alteration is interpreted as a disease-causing mutation. -

Feb 06, 2025

Molecular Diagnostics Laboratory, Catalan Institute of Oncology

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

PVS1, PM2_Supporting, PP4 c.237dup, located in exon 3 of the FH gene, is expected to result in loss of function by premature protein truncation before codon 80, p.(Lys80*).This alteration is expected to result in loss of function by premature protein truncation and nonsense-mediated mRNA decay (PVS1). It is not present in the population database gnomAD v2.1.1, non cancer dataset (PM2_supporting). The SpliceAI algorithm predicts no significant impact on splicing. This mutation has been identified in several individuals diagnosed with renal cancer and multiple leiomyomas (PMID: 31831373 and internal data)(PP4).The variant has been reported as pathogenic in the ClinVar database (2x) but it has not been identified in the LOVD database. Based on currently available information, the variant c.237dup is classified as a pathogenic variant according to ACMG guidelines. -

not provided Pathogenic:1

May 30, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Lys80*) in the FH gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in FH are known to be pathogenic (PMID: 11865300, 21398687). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with cutaneous leiomyomata (PMID: 31831373). ClinVar contains an entry for this variant (Variation ID: 480830). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		0.33
Mutation Taster		=0/200	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs1553341945; hg19: chr1-241680511;