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, no assertion criteria provided | clinical testing | Dr.Nikuei Genetic Center | - | - - |
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 | 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 | 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 | 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. - |