Genetic Variant FLCN:c.249+5G>A (chr17-17227884-C-T) – ACMG Classification: Pathogenic (11 pts)

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PM2PP3PP5_Very_Strong

The NM_144997.7(FLCN):c.249+5G>A variant causes a splice region, intron change. The variant allele was found at a frequency of 0.00000124 in 1,614,038 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 1/1 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

FLCN
NM_144997.7 splice_region, intron

Scores

Clinical Significance

Likely pathogenic criteria provided, multiple submitters, no conflicts P:3

Conservation

PhyloP100: 5.02

Variant links:

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 links:

ENSG00000264187 (HGNC:):

ENSG00000264187 links:

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ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 11 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

PP5

Variant 17-17227884-C-T is Pathogenic according to our data. Variant chr17-17227884-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 418211.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 link	c.249+5G>A		splice_region_variant, intron_variant	Intron 4 of 13	ENST00000285071.9	NP_659434.2	Q8NFG4-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
FLCN	ENST00000285071.9 link	c.249+5G>A		splice_region_variant, intron_variant	Intron 4 of 13	1	NM_144997.7	ENSP00000285071.4		Q8NFG4-1
ENSG00000264187	ENST00000427497.3 link	n.148+106G>A		intron_variant	Intron 4 of 11	1		ENSP00000394249.3		J3QW42

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152252

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1461786

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

727192

show subpopulations

Gnomad4 AFR exome

AF:

0.00

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

AF:

0.00000657

AC:

AN:

152252

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74396

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Pathogenic:1

Jun 01, 2015

GeneDx

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.249+5 G>A variant has not been published as a pathogenic variant, nor has it been reported as a benign polymorphism to our knowledge. This variant was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. One in-silico splice prediction model predicted that c.249+5 G>A destroys the natural splicing donor site of intron 4. Additionally, this substitution occurs at a position that is well conserved in vertebrates. Therefore, this variant is a strong candidate for a pathogenic variant; however, the possibility that it is a benign variant cannot be excluded -

Hereditary cancer-predisposing syndrome

Pathogenic:1

Dec 17, 2024

Ambry Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.249+5G>A intronic variant results from a G to A substitution 5 nucleotides after coding exon 1 in the FLCN gene. This variant was reported in a family with features consistent with Birt-Hogg-Dube syndrome (external communication). This nucleotide position is highly conserved in available vertebrate species. In silico splice site analysis predicts that this alteration will weaken the native splice donor site and may result in the creation or strengthening of a novel splice donor site. RNA studies have demonstrated that this alteration results in abnormal splicing in the set of samples tested (Ambry internal data). Based on the majority of available evidence to date, this variant is likely to be pathogenic. -

Birt-Hogg-Dube syndrome

Pathogenic:1

Nov 21, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change falls in intron 4 of the FLCN gene. It does not directly change the encoded amino acid sequence of the FLCN protein. RNA analysis indicates that this variant induces altered splicing and may result in an absent or altered protein product. This variant is present in population databases (no rsID available, gnomAD 0.007%). This variant has not been reported in the literature in individuals affected with FLCN-related conditions. ClinVar contains an entry for this variant (Variation ID: 418211). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Studies have shown that this variant results in activation of a cryptic splice site, and produces a non-functional protein and/or introduces a premature termination codon (internal data). In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.13

CADD

Benign

DANN

Uncertain

0.99

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.78

Details are displayed if max score is > 0.2

DS_DG_spliceai

0.20

Position offset: 12

DS_DL_spliceai

0.78

Position offset: 5

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over