7-117548727-TTTCTCAC-T

Position:

• chr7-117548727-TTTCTCAC-T

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000492.4(CFTR):​c.1301_1307delCACTTCT​(p.Ser434fs) variant causes a frameshift change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 33)
• Consequence: CFTR NM_000492.4 frameshift
• Clinical Significance: Pathogenic reviewed by expert panel P:6
• Conservation: PhyloP100: 5.37

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]

CFTR-AS1 (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 7-117548727-TTTCTCAC-T is Pathogenic according to our data. Variant chr7-117548727-TTTCTCAC-T is described in ClinVar as [Pathogenic]. Clinvar id is 53225.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr7-117548727-TTTCTCAC-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CFTR	NM_000492.4	c.1301_1307delCACTTCT	p.Ser434fs	frameshift_variant	10/27	ENST00000003084.11	NP_000483.3
CFTR-AS1	NR_149084.1	n.222-6195_222-6189delGTGAGAA		intron_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CFTR	ENST00000003084.11	c.1301_1307delCACTTCT	p.Ser434fs	frameshift_variant	10/27	1	NM_000492.4	ENSP00000003084.6

Frequencies

GnomAD3 genomes Cov.: 33

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:6

Revision: reviewed by expert panel

Submissions by phenotype

Cystic fibrosis Pathogenic:4

Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Dec 18, 2023	Variant summary: CFTR c.1301_1307delCACTTCT (p.Ser434LeufsX6) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Variants downstream of this position have been classified as pathogenic by our laboratory. The variant was absent in 245594 control chromosomes. c.1301_1307delCACTTCT has been reported in the literature in individuals affected with Cystic Fibrosis (eg. Schrijver_2005). Five submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. All submitters classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
Pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Sep 16, 2020	- -
Pathogenic, reviewed by expert panel	research	CFTR2	Dec 08, 2017	- -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	May 19, 2023	For these reasons, this variant has been classified as Pathogenic. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. ClinVar contains an entry for this variant (Variation ID: 53225). This variant is also known as 1429del7 or 1433delCACTTCT. This premature translational stop signal has been observed in individual(s) with clinical features of cystic fibrosis (PMID: 15858154, 23974870). This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Ser434Leufs*6) in the CFTR gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in CFTR are known to be pathogenic (PMID: 1695717, 7691345, 9725922). -

not provided Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	May 23, 2018	- -
Pathogenic, criteria provided, single submitter	clinical testing	Mayo Clinic Laboratories, Mayo Clinic	Jul 10, 2020	PVS1, PM2, PP5 -

Computational scores

Source: dbNSFP v4.3

Splicing

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

Publications

LitVar

Other links and lift over

dbSNP: rs397508186; hg19: chr7-117188781;