17-17227885-T-G

Variant names:

• chr17-17227885-T-G
• rs753648691
• NM_144997.7:c.249+4A>C

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_144997.7(FLCN):​c.249+4A>C variant causes a splice region, intron 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 (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: FLCN NM_144997.7 splice_region, intron
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.59

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]

ENSG00000264187 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FLCN	NM_144997.7	c.249+4A>C		splice_region_variant, intron_variant	Intron 4 of 13	ENST00000285071.9	NP_659434.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
FLCN	ENST00000285071.9	c.249+4A>C		splice_region_variant, intron_variant	Intron 4 of 13	1	NM_144997.7	ENSP00000285071.4
ENSG00000264187	ENST00000427497.3	n.148+105A>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:1

Revision: criteria provided, single submitter

Submissions by phenotype

Birt-Hogg-Dube syndrome Uncertain:1

Jan 27, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant has not been reported in the literature in individuals affected with FLCN-related conditions. 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. Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant is not likely to affect RNA splicing. ClinVar contains an entry for this variant (Variation ID: 951493). This variant is not present in population databases (gnomAD no frequency). 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. It affects a nucleotide within the consensus splice site. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.22
CADD	Benign	20
DANN	Benign	0.97

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.23		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.23		Position offset: 4

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

Publications

LitVar

Other links and lift over

dbSNP: rs753648691; hg19: chr17-17131199;