rs398124534

Variant names:

• chr17-17226275-AT-A
• rs398124534
• NM_144997.7:c.296delA

Variant summary

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

The NM_144997.7(FLCN):​c.296delA​(p.Asp99ValfsTer31) variant causes a frameshift change involving the alteration of a 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. D99D) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: FLCN NM_144997.7 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:10 O:1
• Conservation: PhyloP100: 7.65
• Publications: 4 publications found

Genes affected

FLCN (HGNC:27310): (folliculin) This gene is located within the Smith-Magenis syndrome region on chromosome 17. Mutations in this gene are associated with Birt-Hogg-Dube syndrome, which is characterized by fibrofolliculomas, renal tumors, lung cysts, and pneumothorax. Alternative splicing of this gene results in two transcript variants encoding different isoforms. [provided by RefSeq, Jul 2008]

FLCN Gene-Disease associations (from GenCC):

• Birt-Hogg-Dube syndrome

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Orphanet, ClinGen
• Birt-Hogg-Dube syndrome 1

  Inheritance: AD Classification: DEFINITIVE Submitted by: G2P, Ambry Genetics
• familial spontaneous pneumothorax

  Inheritance: AD Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet, Ambry Genetics
• renal carcinoma

  Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
• colorectal cancer

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics

ENSG00000264187 (HGNC:):

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 17-17226275-AT-A is Pathogenic according to our data. Variant chr17-17226275-AT-A is described in ClinVar as [Pathogenic]. Clinvar id is 96482.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
FLCN	NM_144997.7	c.296delA	p.Asp99ValfsTer31	frameshift_variant	Exon 5 of 14	ENST00000285071.9	NP_659434.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
FLCN	ENST00000285071.9	c.296delA	p.Asp99ValfsTer31	frameshift_variant	Exon 5 of 14	1	NM_144997.7	ENSP00000285071.4
ENSG00000264187	ENST00000427497.3	n.148+1714delA		intron_variant	Intron 4 of 11	1		ENSP00000394249.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:10 Other:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:5

Nov 17, 2023

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The FLCN c.296del; p.Asp99ValfsTer31 variant (rs398124534), also published as c.751delA, is reported in the literature in multiple individuals and families affected with Birt-Hogg-Dube syndrome and has been reported to segregate with disease (Mahtani 2021, Schmidt 2005, Toro 2008). This variant is also absent from the Genome Aggregation Database (v2.1.1), indicating it is not a common polymorphism. This variant causes a frameshift by deleting a single nucleotide, so it is predicted to result in a truncated protein or mRNA subject to nonsense-mediated decay. Based on available information, this variant is considered to be pathogenic. References: Mahtani K et al. Importance of Family History in the Era of Exome Analysis: A Report of a Family with Multiple Concurrent Genetic Diseases. Hum Hered. 2021;86(1-4):28-33. PMID: 34706366. Schmidt LS et al. Germline BHD-mutation spectrum and phenotype analysis of a large cohort of families with Birt-Hogg-Dubé syndrome. Am J Hum Genet. 2005 Jun;76(6):1023-33. PMID: 15852235. Toro JR et al. BHD mutations, clinical and molecular genetic investigations of Birt-Hogg-Dubé syndrome: a new series of 50 families and a review of published reports. J Med Genet. 2008 Jun;45(6):321-31. PMID: 18234728. -

Jan 05, 2024

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The FLCN c.296del (p.Asp99Valfs*31, also known as c.751delA) variant alters the translational reading frame of the FLCN mRNA and causes the premature termination of FLCN protein synthesis. This variant has been reported in the published literature in in individuals with Birt-Hogg-Dube (BHD) syndrome (PMID: 15852235 (2005), 18234728 (2008)). This variant has not been reported in large, multi-ethnic general populations (Genome Aggregation Database, http://gnomad.broadinstitute.org). Based on the available information, this variant is classified as pathogenic. -

Feb 15, 2021

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Frameshift variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss-of-function is a known mechanism of disease; Not observed in large population cohorts (Lek et al., 2016); This variant is associated with the following publications: (PMID: 19802896, 18234728, 21937013, 23757202, 29357828, 15852235) -

Dec 26, 2012

Eurofins Ntd Llc (ga)

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jan 04, 2024

Mayo Clinic Laboratories, Mayo Clinic

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

PP4, PM2_moderate, PVS1 -

Birt-Hogg-Dube syndrome Pathogenic:3 Other:1

Jan 19, 2023

Myriad Genetics, Inc.

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is considered pathogenic. This variant creates a frameshift predicted to result in premature protein truncation. -

-

GenomeConnect, ClinGen

Significance: not provided

Review Status: no classification provided

Collection Method: phenotyping only

GenomeConnect assertions are reported exactly as they appear on the patient-provided report from the testing laboratory. GenomeConnect staff make no attempt to reinterpret the clinical significance of the variant. -

Jul 18, 2016

Genomic Diagnostic Laboratory, Division of Genomic Diagnostics, Children's Hospital of Philadelphia

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Sep 04, 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.Asp99Valfs*31) in the FLCN gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in FLCN are known to be pathogenic (PMID: 15852235). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with Birt-Hogg-Dubé syndrome (PMID: 15852235, 18234728). This variant is also known as c.751delA. ClinVar contains an entry for this variant (Variation ID: 96482). For these reasons, this variant has been classified as Pathogenic. -

Colorectal cancer;C1868193:Familial spontaneous pneumothorax;CN074294:Nonpapillary renal cell carcinoma;CN375946:Birt-Hogg-Dube syndrome 1 Pathogenic:1

Jun 05, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Hereditary cancer-predisposing syndrome Pathogenic:1

Jul 30, 2024

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.296delA pathogenic mutation, located in coding exon 2 of the FLCN gene, results from a deletion of one nucleotide at nucleotide position 296, causing a translational frameshift with a predicted alternate stop codon (p.D99Vfs*31). This alteration was previously described in two unrelated families with Birt-Hogg-Dube syndrome, one of which had two family members with fibrofolliculomas and lung cysts, and one of which consisted of an individual with fibrofolliculomas, renal tumors, lung cysts, and multiple pneumothoraces (Toro JR, J. Med. Genet. 2008 Jun; 45(6):321-31; Schmidt LS, Am. J. Hum. Genet. 2005 Jun; 76(6):1023-33). Of note, this alteration is also designated as c.751delA in the published literature. This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). 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

Name	Calibrated prediction	Score	Prediction
PhyloP100		7.7
Mutation Taster		=0/200	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs398124534; hg19: chr17-17129589;