chr17-17221555-G-A

Position:

• chr17-17221555-G-A

Variant summary

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

The ENST00000285071.9(FLCN):​c.853C>T​(p.Gln285Ter) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,460,752 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. Q285Q) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: FLCN ENST00000285071.9 stop_gained
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:5
• Conservation: PhyloP100: 9.17

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]

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 17-17221555-G-A is Pathogenic according to our data. Variant chr17-17221555-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 253239.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr17-17221555-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
FLCN	NM_144997.7	c.853C>T	p.Gln285Ter	stop_gained	8/14	ENST00000285071.9	NP_659434.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
FLCN	ENST00000285071.9	c.853C>T	p.Gln285Ter	stop_gained	8/14	1	NM_144997.7	ENSP00000285071	P1
FLCN	ENST00000389169.9	c.853C>T	p.Gln285Ter	stop_gained	8/8	1		ENSP00000373821
FLCN	ENST00000466317.1	n.696C>T		non_coding_transcript_exon_variant	2/2	2
FLCN	ENST00000480316.1			downstream_gene_variant		2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1460752 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 726770

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Birt-Hogg-Dube syndrome Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Oct 24, 2023	This sequence change creates a premature translational stop signal (p.Gln285*) 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: 24393238). ClinVar contains an entry for this variant (Variation ID: 253239). For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, no assertion criteria provided	clinical testing	Division of Respiratory Medicine of Juntendo University, Juntendo University Faculty of Medicine and Graduate School of Medicine	Jul 01, 2023	- -
Pathogenic, criteria provided, single submitter	clinical testing	Genomic Diagnostic Laboratory, Division of Genomic Diagnostics, Children's Hospital of Philadelphia	Jul 18, 2016	- -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Jan 07, 2021

Nonsense 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 2016); This variant is associated with the following publications: (PMID: 26763815, 23067074, 29357828, 24393238) -

Hereditary cancer-predisposing syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 19, 2023

The p.Q285* pathogenic mutation (also known as c.853C>T), located in coding exon 5 of the FLCN gene, results from a C to T substitution at nucleotide position 853. This changes the amino acid from a glutamine to a stop codon within coding exon 5. This alteration was identified in a 52-year-old Caucasian male with innumerable facial fibrofolliculomas and trichodiscomas, a history of bilateral spontaneous pneumothoraces, and a unilateral oncocytic/ chromophobe renal tumor with low-grade renal cell carcinoma features; his son reportedly had similar facial skin lesions and history of recurrent pneumothorax (Ge L et al. Med. J. Aust. 2016 Jan;204:28-9). This alteration was also identified in a cohort of Asian Birt-Hogg-Dube syndrome patients (Kumasaka T et al. Histopathology. 2014 Jul;65:100-10). 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
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.65
CADD	Pathogenic	45
DANN	Uncertain	1.0
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.89
FATHMM_MKL	Pathogenic	0.99	D
MutationTaster	Benign	1.0	A;D
Vest4		0.89
GERP RS		6.1
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

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

LitVar

Other links and lift over

dbSNP: rs879255667; hg19: chr17-17124869;