7-117509128-T-C

Position:

• chr7-117509128-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 4P and 1B. PM1 PM2 BP4

The ENST00000003084.11(CFTR):​c.259T>C​(p.Phe87Leu) 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. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as not provided (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. F87I) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: CFTR ENST00000003084.11 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1 O:1
• Conservation: PhyloP100: -0.746

Genes affected

CFTR (HGNC:1884): (CF transmembrane conductance regulator) This gene encodes a member of the ATP-binding cassette (ABC) transporter superfamily. The encoded protein functions as a chloride channel, making it unique among members of this protein family, and controls ion and water secretion and absorption in epithelial tissues. Channel activation is mediated by cycles of regulatory domain phosphorylation, ATP-binding by the nucleotide-binding domains, and ATP hydrolysis. Mutations in this gene cause cystic fibrosis, the most common lethal genetic disorder in populations of Northern European descent. The most frequently occurring mutation in cystic fibrosis, DeltaF508, results in impaired folding and trafficking of the encoded protein. Multiple pseudogenes have been identified in the human genome. [provided by RefSeq, Aug 2017]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 15 uncertain in ENST00000003084.11
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.41837198).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CFTR	NM_000492.4	c.259T>C	p.Phe87Leu	missense_variant	3/27	ENST00000003084.11	NP_000483.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CFTR	ENST00000003084.11	c.259T>C	p.Phe87Leu	missense_variant	3/27	1	NM_000492.4	ENSP00000003084	P2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 25

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1 Other:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Oct 09, 2024

Variant summary: CFTR c.259T>C (p.Phe87Leu) results in a non-conservative amino acid change in the encoded protein sequence. Three of four in-silico tools predict a benign effect of the variant on protein function. The variant was absent in 250824 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.259T>C has been reported in the literature in a compound heterozygous individual affected with Cystic Fibrosis (Bienvenu_1994). These data do not allow any conclusion about variant significance. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication have been ascertained in the context of this evaluation (PMID: 8081395). ClinVar contains an entry for this variant (Variation ID: 53520). Based on the evidence outlined above, the variant was classified as uncertain significance. -

Cystic fibrosis Other:1

not provided, no classification provided

literature only

ClinVar Staff, National Center for Biotechnology Information (NCBI)

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.074
BayesDel_addAF	Uncertain	0.15	D
BayesDel_noAF	Uncertain	-0.020
CADD	Benign	4.4
DANN	Benign	0.61
DEOGEN2	Uncertain	0.67	.;D;.;.;T;.
Eigen	Benign	-1.6
Eigen_PC	Benign	-1.5
FATHMM_MKL	Benign	0.038	N
LIST_S2	Benign	0.66	T;T;T;T;T;T
M_CAP	Benign	0.042	D
MetaRNN	Benign	0.42	T;T;T;T;T;T
MetaSVM	Uncertain	-0.071	T
MutationAssessor	Benign	-0.84	.;N;.;.;.;N
MutationTaster	Benign	1.0	N;N
PrimateAI	Benign	0.41	T
PROVEAN	Benign	2.5	N;N;.;.;N;.
REVEL	Uncertain	0.50
Sift	Benign	1.0	T;T;.;.;T;.
Sift4G	Benign	1.0	T;T;.;.;T;.
Polyphen		0.0	.;B;.;.;.;.
Vest4		0.74
MutPred		0.93		.;Loss of MoRF binding (P = 0.1363);Loss of MoRF binding (P = 0.1363);Loss of MoRF binding (P = 0.1363);Loss of MoRF binding (P = 0.1363);Loss of MoRF binding (P = 0.1363);
MVP		1.0
MPC		0.0038
ClinPred		0.052	T
GERP RS		-5.2
Varity_R		0.12
gMVP		0.77

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: rs397508403; hg19: chr7-117149182;