rs201444561

chr7-117592224-C-A

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM1 PM2

The NM_000492.4(CFTR):c.2057C>A(p.Ser686Tyr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000942 in 1,613,650 control chromosomes in the GnomAD database, including 1 homozygotes. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. S686S) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.000053 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000099 (1 hom.)
• Consequence: CFTR NM_000492.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:9
• Conservation: PhyloP100: 2.10

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 Uncertain_significance. Variant got 4 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 12 uncertain in NM_000492.4
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CFTR	NM_000492.4	c.2057C>A	p.Ser686Tyr	missense_variant	14/27	ENST00000003084.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CFTR	ENST00000003084.11	c.2057C>A	p.Ser686Tyr	missense_variant	14/27	1	NM_000492.4	P2

Frequencies

GnomAD3 genomes AF: 0.0000526 AC: 8 AN: 152166 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000655

Gnomad ASJ AF: 0.000864

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000441

Gnomad OTH AF: 0.000479

GnomAD3 exomes AF: 0.0000723 AC: 18 AN: 248868 Hom.: 0 AF XY: 0.0000740 AC XY: 10 AN XY: 135064

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000290

Gnomad ASJ exome AF: 0.000801

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000714

Gnomad OTH exome AF: 0.000165

GnomAD4 exome AF: 0.0000985 AC: 144 AN: 1461484 Hom.: 1 Cov.: 31 AF XY: 0.000114 AC XY: 83 AN XY: 727014

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.0000224

Gnomad4 ASJ exome AF: 0.000918

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000696

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000899

Gnomad4 OTH exome AF: 0.000182

GnomAD4 genome AF: 0.0000526 AC: 8 AN: 152166 Hom.: 0 Cov.: 33 AF XY: 0.0000673 AC XY: 5 AN XY: 74332

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.0000655

Gnomad4 ASJ AF: 0.000864

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000441

Gnomad4 OTH AF: 0.000479

Alfa AF: 0.000113 Hom.: 0

Bravo AF: 0.0000793

ExAC AF: 0.0000824 AC: 10

EpiCase AF: 0.0000545

EpiControl AF: 0.000119

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:9

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Cystic fibrosis Uncertain:5

Uncertain significance, criteria provided, single submitter	clinical testing	Counsyl	Jan 30, 2017	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Mendelics	Nov 05, 2018	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Oct 27, 2022	This sequence change replaces serine, which is neutral and polar, with tyrosine, which is neutral and polar, at codon 686 of the CFTR protein (p.Ser686Tyr). This variant is present in population databases (rs201444561, gnomAD 0.07%). This missense change has been observed in individual(s) with cystic fibrosis (PMID: 27131402). ClinVar contains an entry for this variant (Variation ID: 550500). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt CFTR protein function. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -
Uncertain significance, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Sep 05, 2021	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Feb 20, 2024	The p.S686Y variant (also known as c.2057C>A), located in coding exon 14 of the CFTR gene, results from a C to A substitution at nucleotide position 2057. The serine at codon 686 is replaced by tyrosine, an amino acid with dissimilar properties. This variant was identified in an individual with primary sclerosing cholangitis (Sheth S et al. Hum. Genet., 2003 Aug;113:286-92). This alteration was also identified in the homozygous state in an individual of Ashkenazi Jewish origin; however, clinical information was not provided (Schwartz KM et al. J Mol Diagn, 2009 May;11:211-5). In addition, this variant was detected in conjunction with other CFTR variants; however, detailed clinical or phase information was not provided (Zhou L et al. Clin. Chem., 2013 Jul;59:1052-61; Sontag MK et al. J. Pediatr., 2016 08;175:150-158.e1). In one study, this variant was identified in two asymptomatic carriers in conjunction with p.F508del (Claustres M et al. Hum. Mutat., 2017 10;38:1297-1315). This amino acid position is well conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on available evidence to date, the clinical significance of this alteration remains unclear. -

CFTR-related disorders Uncertain:2

Uncertain significance, no assertion criteria provided	clinical testing	Natera, Inc.	May 26, 2018	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Apr 27, 2017	This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). Publications were found based on this search. However, the evidence from the literature, in combination with allele frequency data from public databases where available, was not sufficient to rule this variant in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Oct 02, 2023

Variant summary: CFTR c.2057C>A (p.Ser686Tyr) results in a non-conservative amino acid change located in the CFTR regulator domain (IPR025837) 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 7.2e-05 in 248868 control chromosomes (gnomAD). This frequency is not higher than expected for a pathogenic variant in CFTR causing Cystic Fibrosis (7.2e-05 vs 0.013), allowing no conclusion about variant significance. The variant, c.2057C>A, has been reported in the literature in a patient affected with primary sclerosing cholangitis (Sheth_2003), and with pancreatic ductal adenocarcinoma (Zimmermann_2021). The variant was also reported in an individual affected with asthenospermia (Sickkids database), and cystic fibrosis (da Silva Filho_2020), however, no other variants in trans were specified. In addition, the variant was reported without providing an exact clinical phenotype in homozygous state in an individual of Ashkenazi Jewish origin (Schwartz_2009), and in two individuals who also carried other (potentially) causative CFTR variants (phase not specified) (Zhou_2013, Sontag_2016). On the other hand, the variant was found in two asymptomatic compound heterozygotes, with the pathogenic c.1521_1523del (F508del) variant in trans (Claustres_2017). These reports do not provide unequivocal conclusions about association of the variant with Cystic Fibrosis. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 28603918, 15784035, 25735457, 19324992, 12783301, 27131402, 23503723, 33747920, 32819855). Severn ClinVar submitters have assessed the variant since 2014, and all submitters classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Mayo Clinic Laboratories, Mayo Clinic

Sep 20, 2022

PP3 -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.13
BayesDel_addAF	Pathogenic	0.33	D
BayesDel_noAF	Pathogenic	0.43
Cadd	Uncertain	25
Dann	Uncertain	1.0
DEOGEN2	Uncertain	0.75	D;.;D;.
Eigen	Pathogenic	0.71
Eigen_PC	Pathogenic	0.67
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Uncertain	0.94	D;D;D;D
M_CAP	Pathogenic	0.66	D
MetaRNN	Uncertain	0.64	D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.4	M;.;.;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.58	T
PROVEAN	Uncertain	-2.5	N;.;N;.
REVEL	Pathogenic	0.82
Sift	Uncertain	0.019	D;.;D;.
Sift4G	Pathogenic	0.0	D;.;D;.
Polyphen		1.0	D;.;.;.
Vest4		0.59
MVP		1.0
MPC		0.0063
ClinPred		0.19	T
GERP RS		5.6
Varity_R		0.33
gMVP		0.71

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: rs201444561; hg19: chr7-117232278;