rs765628527

Positions:

• chr17-17216413-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 3P and 2B. PM2 PP3 BP6 BS2_Supporting

The NM_144997.7(FLCN):​c.1267C>T​(p.His423Tyr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,461,446 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/23 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. H423Q) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: FLCN NM_144997.7 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:1
• Conservation: PhyloP100: 2.33

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 Uncertain_significance. Variant got 1 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.
• BP6: Variant 17-17216413-G-A is Benign according to our data. Variant chr17-17216413-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 582392.We mark this variant Likely_benign, oryginal submissions are: {Benign=1, Uncertain_significance=1}.
• BS2: High AC in GnomAdExome4 at 5 AD gene. Variant has AC lower than other variant known as pathogenic in the gene, so the strength is limited to Supporting.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
FLCN	NM_144997.7	c.1267C>T	p.His423Tyr	missense_variant	11/14	ENST00000285071.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
FLCN	ENST00000285071.9	c.1267C>T	p.His423Tyr	missense_variant	11/14	1	NM_144997.7	P1
MPRIP	ENST00000578209.5	c.*18-1077G>A		intron_variant		3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.0000121 AC: 3 AN: 248930 Hom.: 0 AF XY: 0.0000148 AC XY: 2 AN XY: 134892

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.000163

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461446 Hom.: 0 Cov.: 31 AF XY: 0.00000550 AC XY: 4 AN XY: 727032

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.000126

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

ExAC AF: 0.0000165 AC: 2

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Birt-Hogg-Dube syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Dec 01, 2023

This sequence change replaces histidine, which is basic and polar, with tyrosine, which is neutral and polar, at codon 423 of the FLCN protein (p.His423Tyr). This variant is present in population databases (rs765628527, gnomAD 0.02%). 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: 582392). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt FLCN protein function with a negative predictive value of 80%. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. 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. -

Hereditary cancer-predisposing syndrome Benign:1

Benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Jun 11, 2024

This alteration is classified as benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.086
BayesDel_addAF	Benign	-0.22	T
BayesDel_noAF	Benign	-0.28
CADD	Benign	22
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.45	T
Eigen	Benign	-0.48
Eigen_PC	Benign	-0.38
FATHMM_MKL	Uncertain	0.91	D
LIST_S2	Uncertain	0.86	D
M_CAP	Uncertain	0.11	D
MetaRNN	Benign	0.19	T
MetaSVM	Uncertain	0.14	D
MutationAssessor	Benign	1.4	L
MutationTaster	Benign	0.66	D
PrimateAI	Benign	0.33	T
PROVEAN	Benign	-0.89	N
REVEL	Benign	0.21
Sift	Benign	0.054	T
Sift4G	Benign	0.19	T
Polyphen		0.0060	B
Vest4		0.45
MutPred		0.45		Gain of sheet (P = 0.0477);
MVP		0.21
MPC		0.45
ClinPred		0.14	T
GERP RS		4.9
Varity_R		0.17
gMVP		0.30

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.72		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.72		Position offset: 2

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

Publications

LitVar

Other links and lift over

dbSNP: rs765628527; hg19: chr17-17119727;