chr1-241517209-C-CT

Position:

• chr1-241517209-C-CT

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000143.4(FH):​c.239dupA​(p.Ile81fs) variant causes a frameshift change. 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. K80K) 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:6
• Conservation: PhyloP100: 5.58

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 (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 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 1-241517209-C-CT is Pathogenic according to our data. Variant chr1-241517209-C-CT is described in ClinVar as [Pathogenic]. Clinvar id is 393558.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
FH	NM_000143.4	c.239dupA	p.Ile81fs	frameshift_variant	2/10	ENST00000366560.4	NP_000134.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
FH	ENST00000366560.4	c.239dupA	p.Ile81fs	frameshift_variant	2/10	1	NM_000143.4	ENSP00000355518.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary leiomyomatosis and renal cell cancer Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Genomic Diagnostic Laboratory, Division of Genomic Diagnostics, Children's Hospital of Philadelphia	Jan 17, 2017	- -
Pathogenic, criteria provided, single submitter	clinical testing	Myriad Genetics, Inc.	Feb 23, 2023	This variant is considered pathogenic. This variant creates a frameshift predicted to result in premature protein truncation. -

not provided Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Nov 25, 2023	This sequence change creates a premature translational stop signal (p.Ile81Aspfs*14) 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 hereditary leiomyomatosis and renal cell cancer (HLRCC) (PMID: 15937070). This variant is also known as c.111insA. ClinVar contains an entry for this variant (Variation ID: 393558). For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Dec 28, 2016	This duplication of one nucleotide in FH is denoted c.239dupA at the cDNA level and p.Ile81AspfsX14 (I81DfsX14) at the protein level. The normal sequence, with the base that is duplicated in brackets, is TTTA[dupA]GATT. The duplication causes a frameshift which changes an Isoleucine to an Aspartic Acid at codon 81 and creates a premature stop codon at position 14 of the new reading frame. This variant is predicted to cause loss of normal protein function through either protein truncation or nonsense-mediated mRNA decay. FH c.239dupA, previously published as c.111insA, has been reported in an individual with early-onset renal cancer and at least one cutaneous leiomyoma who had a family history of renal cell carcinoma (Wei 2006). It was also observed in a papillary and tubulocystic renal cell carcinoma that demonstrated negative FH and positive 2SC staining by IHC (Smith 2016, Trpkov 2016). We consider this variant to be pathogenic. -

Fumarase deficiency Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Baylor Genetics

May 04, 2023

- -

Hereditary cancer-predisposing syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Mar 04, 2024

The c.239dupA pathogenic mutation, located in coding exon 2 of the FH gene, results from a duplication of A at nucleotide position 239, causing a translational frameshift with a predicted alternate stop codon (p.I81Dfs*14). This alteration was identified in a 26 year-old African-American male affected with renal cancer and cutaneous leiomyoma (Wei MH et al. J. Med. Genet., 2006 Jan;43:18-27). This alteration is also described in the literature as 111insA. In addition to the clinical data presented in the literature, 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. -

Computational scores

Source: dbNSFP v4.3

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

Publications

LitVar

Other links and lift over

dbSNP: rs1553341942; hg19: chr1-241680509;