rs397508490

Positions:

• chr7-117530930-T-C
• chr7-117530930-T-G

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PM1 PM2 PM5 PP3_Strong PP5_Moderate

The NM_000492.4(CFTR):​c.305T>C​(p.Leu102Pro) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L102R) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: CFTR NM_000492.4 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1 O:1
• Conservation: PhyloP100: 4.54

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 Pathogenic. Variant got 12 ACMG points.

• PM1: In a topological_domain Extracellular (size 23) in uniprot entity CFTR_HUMAN there are 19 pathogenic changes around while only 0 benign (100%) in NM_000492.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr7-117530930-T-G is described in Lovd as [Pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.992
• PP5: Variant 7-117530930-T-C is Pathogenic according to our data. Variant chr7-117530930-T-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 53642.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CFTR	NM_000492.4	c.305T>C	p.Leu102Pro	missense_variant	4/27	ENST00000003084.11	NP_000483.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CFTR	ENST00000003084.11	c.305T>C	p.Leu102Pro	missense_variant	4/27	1	NM_000492.4	ENSP00000003084.6

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1 Other:1

Revision: criteria provided, single submitter

Submissions by phenotype

Cystic fibrosis Pathogenic:1 Other:1

Likely pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Nov 21, 2020	In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. Experimental studies have shown that this variant affects CFTR protein function (PMID: 21708286). This variant has been observed in individual(s) with cystic fibrosis (PMID: 21708286). In at least one individual the data is consistent with the variant being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 53642). This variant is not present in population databases (ExAC no frequency). This sequence change replaces leucine with proline at codon 102 of the CFTR protein (p.Leu102Pro). The leucine residue is highly conserved and there is a moderate physicochemical difference between leucine and proline. -
not provided, no classification provided	literature only	ClinVar Staff, National Center for Biotechnology Information (NCBI)	-	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.52	D
BayesDel_noAF	Pathogenic	0.51
CADD	Pathogenic	28
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.94	.;D;.;.;D;.
Eigen	Pathogenic	0.77
Eigen_PC	Pathogenic	0.74
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Uncertain	0.93	D;D;D;D;D;D
M_CAP	Pathogenic	0.92	D
MetaRNN	Pathogenic	0.99	D;D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.8	.;M;.;.;.;M
PrimateAI	Uncertain	0.78	T
PROVEAN	Pathogenic	-6.6	D;D;.;.;D;.
REVEL	Pathogenic	0.94
Sift	Pathogenic	0.0	D;D;.;.;D;.
Sift4G	Pathogenic	0.0	D;D;.;.;D;.
Polyphen		1.0	.;D;.;.;.;.
Vest4		0.96
MutPred		0.97		.;Loss of stability (P = 0.0884);Loss of stability (P = 0.0884);Loss of stability (P = 0.0884);Loss of stability (P = 0.0884);Loss of stability (P = 0.0884);
MVP		1.0
MPC		0.013
ClinPred		0.99	D
GERP RS		5.7
Varity_R		0.99
gMVP		0.99

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: rs397508490; hg19: chr7-117170984;