rs200955612

chr7-117664821-T-Achr7-117664821-T-C

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PM1 PM2 PM5 PP3_Strong PP5_Very_Strong

The NM_000492.4(CFTR):c.4097T>A(p.Ile1366Asn) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,736 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I1366T) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: CFTR NM_000492.4 missense
• Clinical Significance: Pathogenic reviewed by expert panel P:3 U:1
• Conservation: PhyloP100: 7.52

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 18 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 15 uncertain 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 chr7-117664821-T-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 526019.We mark this variant Likely_pathogenic, oryginal submissions are: {Pathogenic=1, Uncertain_significance=5, Likely_pathogenic=1}.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.99
• PP5: Variant 7-117664821-T-A is Pathogenic according to our data. Variant chr7-117664821-T-A is described in ClinVar as [Pathogenic]. Clinvar id is 551822.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr7-117664821-T-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CFTR	NM_000492.4	c.4097T>A	p.Ile1366Asn	missense_variant	25/27	ENST00000003084.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CFTR	ENST00000003084.11	c.4097T>A	p.Ile1366Asn	missense_variant	25/27	1	NM_000492.4	P2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251286 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135796

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: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461736 Hom.: 0 Cov.: 32 AF XY: 0.00000275 AC XY: 2 AN XY: 727188

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3 Uncertain:1

Revision: reviewed by expert panel

Submissions by phenotype

Cystic fibrosis Pathogenic:3 Uncertain:1

Pathogenic, criteria provided, single submitter	curation	Institute of Human Genetics, University of Leipzig Medical Center	Sep 05, 2022	This variant was identified in 2 unrelated patients with a clinically confirmed diagnosis of cystic fibrosis. The variant was classified in the context of a project re-classifying variants in the German Cystic Fibrosis Registry (Muko.e.V.). Link: https://www.muko.info/angebote/qualitaetsmanagement/register/cf-einrichtungen/mukoweb. Criteria applied: PM2_SUP, PM3_STR, PM5_STR, PP3 -
Likely pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Jul 18, 2023	Variant summary: CFTR c.4097T>A (p.Ile1366Asn) results in a non-conservative amino acid change located in the ATP-binding domain (IPR003439) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 4e-06 in 251286 control chromosomes (i.e., 1 heterozygote; gnomAD v2.1 Exomes dataset). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.4097T>A has been reported in the literature in at least two compound heterozygous individuals affected with Cystic Fibrosis (e.g., Krenkova_2012, Levy_2016, Geurts_2020, Raraigh_2022). These data indicate that the variant is likely to be associated with disease. At least one unpublished preprint reports experimental evidence evaluating an impact on protein function, finding that the variant results in <10% of normal chloride channel conductance relative to wild type (e.g., Bihler_2023, bioRxiv, no PMID). The following publications have been ascertained in the context of this evaluation (PMID: 32084388, 23276700, 26671754, 35527187). Three submitters have reported clinical-significance assessments for this variant to ClinVar after 2014; two submitters classified the variant as pathogenic and one submitter classified it as uncertain significance. Based on the evidence outlined above, the variant was classified as likely pathogenic. -
Uncertain significance, criteria provided, single submitter	clinical testing	Counsyl	May 15, 2017	- -
Pathogenic, reviewed by expert panel	research	CFTR2	Jan 10, 2020	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.95
BayesDel_addAF	Pathogenic	0.49	D
BayesDel_noAF	Pathogenic	0.47
Cadd	Pathogenic	28
Dann	Uncertain	0.99
DEOGEN2	Pathogenic	0.98	D;D;.
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.96
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.96	D;D;D
M_CAP	Pathogenic	0.94	D
MetaRNN	Pathogenic	0.99	D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.7	H;.;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Pathogenic	0.86	D
PROVEAN	Pathogenic	-5.8	D;D;.
REVEL	Pathogenic	0.96
Sift	Pathogenic	0.0	D;D;.
Sift4G	Pathogenic	0.0	D;D;.
Polyphen		1.0	D;.;.
Vest4		0.99
MutPred		0.94		Gain of disorder (P = 0.0121);.;.;
MVP		1.0
MPC		0.012
ClinPred		1.0	D
GERP RS		5.9
Varity_R		0.99
gMVP		0.96

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: rs200955612; hg19: chr7-117304875;