chr17-17213692-G-A

Position:

• chr17-17213692-G-A

Variant summary

Our verdict is Likely benign. Variant got -6 ACMG points: 0P and 6B. BP4_Moderate BS2

The NM_144997.7(FLCN):​c.1703C>T​(p.Thr568Met) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000547 in 1,461,878 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. T568A) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000055 (0 hom.)
• Consequence: FLCN NM_144997.7 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:4
• Conservation: PhyloP100: 7.70

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 -6 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.24676847).
• BS2: High AC in GnomAdExome4 at 8 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
FLCN	NM_144997.7	c.1703C>T	p.Thr568Met	missense_variant	14/14	ENST00000285071.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
FLCN	ENST00000285071.9	c.1703C>T	p.Thr568Met	missense_variant	14/14	1	NM_144997.7	P1
MPRIP	ENST00000578209.5	c.*18-3798G>A		intron_variant		3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251492 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135920

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000547 AC: 8 AN: 1461878 Hom.: 0 Cov.: 30 AF XY: 0.00000413 AC XY: 3 AN XY: 727234

Gnomad4 AFR exome AF: 0.0000896

Gnomad4 AMR exome AF: 0.0000224

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Birt-Hogg-Dube syndrome Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Dec 28, 2023	This sequence change replaces threonine, which is neutral and polar, with methionine, which is neutral and non-polar, at codon 568 of the FLCN protein (p.Thr568Met). This variant is present in population databases (rs781733528, gnomAD 0.0009%). 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: 460606). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Baylor Genetics	Jul 21, 2023	- -

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Center for Genomic Medicine, Rigshospitalet, Copenhagen University Hospital

Jul 31, 2024

- -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

May 18, 2024

The p.T568M variant (also known as c.1703C>T), located in coding exon 11 of the FLCN gene, results from a C to T substitution at nucleotide position 1703. The threonine at codon 568 is replaced by methionine, an amino acid with similar properties. This amino acid position is not well conserved in available vertebrate species. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.15
BayesDel_addAF	Uncertain	0.15	D
BayesDel_noAF	Uncertain	-0.020
CADD	Uncertain	26
DANN	Uncertain	0.99
DEOGEN2	Benign	0.30	T
Eigen	Benign	0.013
Eigen_PC	Benign	0.16
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.92	D
M_CAP	Uncertain	0.12	D
MetaRNN	Benign	0.25	T
MetaSVM	Uncertain	0.022	D
MutationAssessor	Benign	0.0	N
MutationTaster	Benign	0.98	D
PrimateAI	Uncertain	0.59	T
PROVEAN	Benign	-0.95	N
REVEL	Uncertain	0.44
Sift	Uncertain	0.0030	D
Sift4G	Uncertain	0.0080	D
Polyphen		0.52	P
Vest4		0.43
MutPred		0.23		Loss of glycosylation at T568 (P = 0.0185);
MVP		0.37
MPC		0.42
ClinPred		0.70	D
GERP RS		4.7
Varity_R		0.18
gMVP		0.34

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

Publications

LitVar

Other links and lift over

dbSNP: rs781733528; hg19: chr17-17117006; COSMIC: COSV53257125; COSMIC: COSV53257125;