rs397508200

chr7-117559463-G-Achr7-117559463-G-C

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PVS1_Moderate PM2 PP3_Strong PP5_Very_Strong

The NM_000492.4(CFTR):c.1393-1G>A variant causes a splice acceptor change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000188 in 1,595,018 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★★).

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000019 (0 hom.)
• Consequence: CFTR NM_000492.4 splice_acceptor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic reviewed by expert panel P:13
• Conservation: PhyloP100: 9.43

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 16 ACMG points.

• PVS1: Splicing variant, NOT destroyed by nmd, known LOF gene, truncates exone, which is 0.04298897 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 7-117559463-G-A is Pathogenic according to our data. Variant chr7-117559463-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 53242.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr7-117559463-G-A is described in Lovd as [Pathogenic]. Variant chr7-117559463-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CFTR	NM_000492.4	c.1393-1G>A		splice_acceptor_variant		ENST00000003084.11
CFTR-AS1	NR_149084.1	n.221+1270C>T		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CFTR	ENST00000003084.11	c.1393-1G>A		splice_acceptor_variant		1	NM_000492.4	P2

Frequencies

GnomAD3 genomes AF: 0.0000132 AC: 2 AN: 152088 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000415

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000319 AC: 8 AN: 251162 Hom.: 0 AF XY: 0.0000516 AC XY: 7 AN XY: 135766

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.000261

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000194 AC: 28 AN: 1442812 Hom.: 0 Cov.: 27 AF XY: 0.0000334 AC XY: 24 AN XY: 719224

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.000326

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152206 Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1 AN XY: 74420

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.000415

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ExAC AF: 0.0000494 AC: 6

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:13

Revision: reviewed by expert panel

Submissions by phenotype

Cystic fibrosis Pathogenic:7

Pathogenic, criteria provided, single submitter	curation	CFTR-France	Jan 29, 2018	- -
Pathogenic, reviewed by expert panel	research	CFTR2	Mar 17, 2017	- -
Pathogenic, criteria provided, single submitter	clinical testing	Arcensus	Feb 01, 2013	- -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Mar 30, 2017	Variant summary: The c.1393-1G>A in CFTR gene is a splice-site variant that alters a highly conserved nucleotide. 5/5 in silico tools via Alamut predict this variant to disrupt a canonical splicing acceptor sequence, although these predictions are yet to be confirmed by the functional studies. The variant is present in control dataset of ExAC at a low frequency of 0.000049 (6/121108 chrs tested) which does not exceed the estimated maximum allele frequency for a pathogenic allele in this gene (0.0129). This variant appears to be very common in Palestina (Siryani, 2015). The variant was found homozygously or in compound heterozygosity in multiple affected individuals with established dx of CF. Patients, homozygous for the variant of interest, presented with elevated sweat Cl- (ranging from 110 to 148 mmol/L) and PI. Lastly, multiple reputable databases/diagnostic centers classified the variant of interest as Pathogenic. Taken together, the variant was classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jan 05, 2024	This sequence change affects an acceptor splice site in intron 10 of the CFTR gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in CFTR are known to be pathogenic (PMID: 1695717, 7691345, 9725922). This variant is present in population databases (rs397508200, gnomAD 0.03%). Disruption of this splice site has been observed in individual(s) with cystic fibrosis and congenital bilateral absence of the vas deferens (PMID: 7682196, 9239681, 9482579, 15727251, 17662673, 18373402, 18782298, 21198395, 21909392, 23933162, 25688174, 26208274, 26708955). This variant is also known as c.1525-1G>A. ClinVar contains an entry for this variant (Variation ID: 53242). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Oct 18, 2013	The 1393-1G>A variant in CFTR causes cystic fibrosis when combined with another CF-causing variant. It has been previously identified in 2 homozygous and 3 comp ound heterozygous individuals with cystic fibrosis and was found to segregate wi th disease in 1 family member (Dork 1993, Ramalho 2003, Wahab 2004, Ashavaid 200 5, Nikolic 2013). It has not been identified in large population studies. This v ariant occurs in the invariant region (+/- 1,2) of the splice consensus sequence and is predicted to cause altered splicing leading to an abnormal or absent pro tein (Ramalho 2003). In summary, this variant meets our criteria to be classifie d as pathogenic (http://pcpgm.partners.org/LMM) based upon segregation studies, absence from controls, and functional evidence. -
Pathogenic, criteria provided, single submitter	clinical testing	Ambry Genetics	Aug 17, 2022	The c.1393-1G>A intronic pathogenic mutation (also known as 1525-1G>A) results from a G to A substitution one nucleotide upstream from coding exon 11 of the CFTR gene. This mutation was first reported in an Afghani individual with elevated sweat chloride levels and clinical features of cystic fibrosis (CF); however, a second CFTR alteration was not identified (Dörk T et al. Genomics, 1993 Mar;15:688-91). A Serbian individual homozygous for this mutation presented with liver steatosis at age 7 years and later developed respiratory symptoms; he had mild pancreatic insufficiency and elevated sweat chloride levels (Nikolic A et al. J. Cyst. Fibros., 2014 Jan;13:111-3). Splicing analysis in colonic biopsies from two related Pakistani individuals with CF with c.1393-1G>A and p.F508del demonstrated exon skipping or the use of alternative splice sites due to the intronic alteration. Furthermore, the same study demonstrated that CFTR mediated chloride secretion was absent in the colonic biopsies of the affected individuals (Ramalho AS et al. J. Med. Genet., 2003 Jul;40:e88). In addition to the clinical data presented in the literature, alterations that disrupt the canonical splice site are expected to cause aberrant splicing, resulting in an abnormal protein or a transcript that is subject to nonsense-mediated mRNA decay. As such, this alteration is classified as a disease-causing mutation. -

CFTR-related disorder Pathogenic:2

Pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Mar 17, 2017	- -
Pathogenic, criteria provided, single submitter	clinical testing	PreventionGenetics, part of Exact Sciences	Dec 30, 2023	The CFTR c.1393-1G>A variant is predicted to disrupt the AG splice acceptor site and interfere with normal splicing. This variant, previously described as c.1525-1G>A using legacy nomenclature, has been reported to be causative for cystic fibrosis (Castellani et al. 2008. PubMed ID: 18456578; Supplemental table 2, Sosnay et al. 2013. PubMed ID: 23974870). The c.1393-1G>A variant has also been reported in patient with idiopathic chronic pancreatitis who had a corresponding pathogenic variant in the SPINK1 gene (Supplemental table 1, Midha et al. 2010. PubMed ID: 20551465). This variant is reported in 0.026% of alleles in individuals of South Asian descent in gnomAD. Variants that disrupt the consensus splice acceptor site in CFTR are expected to be pathogenic. This variant is interpreted as pathogenic. -

not specified Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Mar 15, 2017

- -

Cystic fibrosis;C0403814:Congenital bilateral aplasia of vas deferens from CFTR mutation Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Baylor Genetics

-

- -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Quest Diagnostics Nichols Institute San Juan Capistrano

Apr 08, 2017

- -

Bronchiectasis with or without elevated sweat chloride 1 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Baylor Genetics

Sep 21, 2023

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.42	D
BayesDel_noAF	Pathogenic	0.41
Cadd	Pathogenic	32
Dann	Uncertain	1.0
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.1
FATHMM_MKL	Pathogenic	0.99	D
MutationTaster	Benign	1.0	D;D
GERP RS		5.5

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_AL_spliceai		1.0		Position offset: 1

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

Publications

LitVar

Other links and lift over

dbSNP: rs397508200; hg19: chr7-117199517;