17-17227962-C-G

Variant names:

• chr17-17227962-C-G
• rs374969279
• NM_144997.7:c.176G>C

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM2 BP4

The NM_144997.7(FLCN):​c.176G>C​(p.Arg59Pro) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R59L) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 33)
• Consequence: FLCN NM_144997.7 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 2.17
• Publications: 1 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: Uncertain_significance. The variant received 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.37110424).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FLCN	NM_144997.7	c.176G>C	p.Arg59Pro	missense_variant	Exon 4 of 14	ENST00000285071.9	NP_659434.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
FLCN	ENST00000285071.9	c.176G>C	p.Arg59Pro	missense_variant	Exon 4 of 14	1	NM_144997.7	ENSP00000285071.4
ENSG00000264187	ENST00000427497.3	n.148+28G>C		intron_variant	Intron 4 of 11	1		ENSP00000394249.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1

Jun 21, 2022

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.R59P variant (also known as c.176G>C), located in coding exon 1 of the FLCN gene, results from a G to C substitution at nucleotide position 176. The arginine at codon 59 is replaced by proline, an amino acid with dissimilar properties. This amino acid position is conserved. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Birt-Hogg-Dube syndrome Uncertain:1

Apr 25, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

ClinVar contains an entry for this variant (Variation ID: 851547). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. 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 replaces arginine, which is basic and polar, with proline, which is neutral and non-polar, at codon 59 of the FLCN protein (p.Arg59Pro). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.14
BayesDel_addAF	Pathogenic	0.25	D
BayesDel_noAF	Uncertain	0.12
CADD	Benign	16
DANN	Uncertain	0.99
DEOGEN2	Benign	0.25	T;.;T
Eigen	Benign	-0.035
Eigen_PC	Benign	0.039
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.91	D;D;D
M_CAP	Uncertain	0.099	D
MetaRNN	Benign	0.37	T;T;T
MetaSVM	Uncertain	0.48	D
MutationAssessor	Benign	1.9	L;L;.
PhyloP100		2.2
PrimateAI	Benign	0.35	T
PROVEAN	Benign	-1.4	N;N;N
REVEL	Uncertain	0.51
Sift	Benign	0.27	T;T;D
Sift4G	Benign	0.26	T;T;T
Polyphen		0.0	B;D;.
Vest4		0.75
MutPred		0.28		Loss of catalytic residue at R59 (P = 0.0088);Loss of catalytic residue at R59 (P = 0.0088);.;
MVP		0.11
MPC		0.60
ClinPred		0.52	D
GERP RS		5.5
Varity_R		0.38
gMVP		0.38

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: rs374969279; hg19: chr17-17131276;