17-17213794-TTC-TTCTC

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PVS1_Strong PM2 PP5_Moderate

The NM_144997.7(FLCN):c.1600_1601insGA(p.Lys534ArgfsTer4) 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. K534K) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: FLCN NM_144997.7 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 4.79

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]

MPRIP (HGNC:30321): (myosin phosphatase Rho interacting protein) Enables cadherin binding activity. Predicted to be involved in actin filament organization. Located in actin cytoskeleton and cytosol. [provided by Alliance of Genome Resources, Apr 2022]

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 8 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 17-17213794-T-TTC is Pathogenic according to our data. Variant chr17-17213794-T-TTC is described in ClinVar as [Pathogenic]. Clinvar id is 460604.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
FLCN	NM_144997.7	c.1600_1601insGA	p.Lys534ArgfsTer4	frameshift_variant	14/14	ENST00000285071.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
FLCN	ENST00000285071.9	c.1600_1601insGA	p.Lys534ArgfsTer4	frameshift_variant	14/14	1	NM_144997.7	P1
MPRIP	ENST00000578209.5	c.*18-3694_*18-3693dup		intron_variant		3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Birt-Hogg-Dube syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Jan 17, 2022

For these reasons, this variant has been classified as Pathogenic. This variant disrupts a region of the FLCN protein in which other variant(s) (p.Trp553Arg) have been determined to be pathogenic (Invitae; external communications). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. This variant disrupts the FNIP1/2 interaction domain, which has been shown to be important for AMPK-mediated mTOR signaling pathways (PMID: 17028174, 18403135, 18663353, 22977732). While functional studies have not been performed to directly test the effect of this variant on FLCN protein function, this suggests that disruption of this region of the protein may be causative of disease. ClinVar contains an entry for this variant (Variation ID: 460604). This variant has not been reported in the literature in individuals affected with FLCN-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Lys534Argfs*4) in the FLCN gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 46 amino acid(s) of the FLCN protein. -

Computational scores

Source: dbNSFP v4.3

Splicing

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

Publications

LitVar

Other links and lift over

dbSNP: rs1439151268; hg19: chr17-17117108;