rs41419545

Positions:

• chr17-17215284-C-A
• chr17-17215284-C-G
• chr17-17215284-C-T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_144997.7(FLCN):​c.1333G>T​(p.Ala445Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,806 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/21 in silico tools predict 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. A445T) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: FLCN NM_144997.7 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: -0.0320

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_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.050207734).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
FLCN	NM_144997.7	c.1333G>T	p.Ala445Ser	missense_variant	12/14	ENST00000285071.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
FLCN	ENST00000285071.9	c.1333G>T	p.Ala445Ser	missense_variant	12/14	1	NM_144997.7	P1
MPRIP	ENST00000578209.5	c.*18-2206C>A		intron_variant		3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461806 Hom.: 0 Cov.: 34 AF XY: 0.00000138 AC XY: 1 AN XY: 727190

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jan 16, 2019

The p.A445S variant (also known as c.1333G>T), located in coding exon 9 of the FLCN gene, results from a G to T substitution at nucleotide position 1333. The alanine at codon 445 is replaced by serine, an amino acid with similar properties. This amino acid position is poorly conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Birt-Hogg-Dube syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Sep 07, 2022

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. ClinVar contains an entry for this variant (Variation ID: 818969). 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 alanine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 445 of the FLCN protein (p.Ala445Ser). 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.069
BayesDel_addAF	Benign	-0.076	T
BayesDel_noAF	Benign	-0.35
CADD	Benign	0.014
DANN	Benign	0.61
DEOGEN2	Benign	0.30	T
Eigen	Benign	-1.7
Eigen_PC	Benign	-1.8
FATHMM_MKL	Benign	0.074	N
LIST_S2	Benign	0.76	T
M_CAP	Benign	0.085	D
MetaRNN	Benign	0.050	T
MetaSVM	Benign	-0.56	T
MutationAssessor	Benign	0.0	N
MutationTaster	Benign	1.0	N
PrimateAI	Benign	0.29	T
PROVEAN	Benign	0.64	N
REVEL	Benign	0.18
Sift	Benign	0.78	T
Sift4G	Benign	0.53	T
Polyphen		0.014	B
Vest4		0.22
MutPred		0.29		Gain of sheet (P = 0.0125);
MVP		0.36
MPC		0.34
ClinPred		0.036	T
GERP RS		-7.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.039
gMVP		0.22

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs41419545; hg19: chr17-17118598;