rs1800086

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM1BS2_Supporting

The NM_000492.4(CFTR):​c.1052C>G​(p.Thr351Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00018 in 1,614,014 control chromosomes in the GnomAD database, including 2 homozygotes. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.00022 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00018 ( 2 hom. )

Consequence

CFTR
NM_000492.4 missense

Scores

8
9
2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:12B:2

Conservation

PhyloP100: 7.43
Variant links:
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 1 ACMG points.

PM1
In a transmembrane_region Helical; Name=6 (size 18) in uniprot entity CFTR_HUMAN there are 9 pathogenic changes around while only 1 benign (90%) in NM_000492.4
BS2
High Homozygotes in GnomAdExome4 at 2 AR geneVariant has number of homozygotes lower than other variant known as pathogenic in the gene, so the strength is limited to Supporting.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CFTRNM_000492.4 linkc.1052C>G p.Thr351Ser missense_variant Exon 8 of 27 ENST00000003084.11 NP_000483.3 P13569-1A0A024R730

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CFTRENST00000003084.11 linkc.1052C>G p.Thr351Ser missense_variant Exon 8 of 27 1 NM_000492.4 ENSP00000003084.6 P13569-1

Frequencies

GnomAD3 genomes
AF:
0.000223
AC:
34
AN:
152164
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.000121
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000786
Gnomad ASJ
AF:
0.000576
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000206
Gnomad OTH
AF:
0.000478
GnomAD3 exomes
AF:
0.000183
AC:
46
AN:
251162
Hom.:
0
AF XY:
0.000169
AC XY:
23
AN XY:
135728
show subpopulations
Gnomad AFR exome
AF:
0.000308
Gnomad AMR exome
AF:
0.000318
Gnomad ASJ exome
AF:
0.000695
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000194
Gnomad OTH exome
AF:
0.000163
GnomAD4 exome
AF:
0.000176
AC:
257
AN:
1461732
Hom.:
2
Cov.:
31
AF XY:
0.000171
AC XY:
124
AN XY:
727178
show subpopulations
Gnomad4 AFR exome
AF:
0.000149
Gnomad4 AMR exome
AF:
0.000425
Gnomad4 ASJ exome
AF:
0.000536
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.0000187
Gnomad4 NFE exome
AF:
0.000150
Gnomad4 OTH exome
AF:
0.000613
GnomAD4 genome
AF:
0.000223
AC:
34
AN:
152282
Hom.:
0
Cov.:
32
AF XY:
0.000148
AC XY:
11
AN XY:
74472
show subpopulations
Gnomad4 AFR
AF:
0.000120
Gnomad4 AMR
AF:
0.000785
Gnomad4 ASJ
AF:
0.000576
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.000206
Gnomad4 OTH
AF:
0.000473
Alfa
AF:
0.000223
Hom.:
0
Bravo
AF:
0.000280
TwinsUK
AF:
0.00
AC:
0
ALSPAC
AF:
0.000259
AC:
1
ESP6500AA
AF:
0.000227
AC:
1
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.000173
AC:
21
EpiCase
AF:
0.000164
EpiControl
AF:
0.000237

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:1Uncertain:12Benign:2
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Cystic fibrosis Uncertain:5Benign:1
Jul 22, 2021
Genome-Nilou Lab
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

May 28, 2020
Genome Diagnostics Laboratory, The Hospital for Sick Children
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Dec 07, 2022
Ambry Genetics
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Nov 05, 2018
Mendelics
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Oct 11, 2021
Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: research

This imprecision led to the belief that this variant is pathogenic. Despite this variant has been classified and reclassified over the course of time as pathogenic and lately as likely pathogenic (by Mendelics and Invitae), new functional evidence has shown that this variant does not alter CFTR function even when located in the same allele (in cis) as NM_000492.4(CFTR):2552G>T; p.Arg851Leu) and in trans with the most common pathogenic variant p.Phe508del (NM_000492.4(CFTR):1521_1523delCTT). Although in a pathogenic range due to its very low frequency in public databases (1000 Genomes, GnomAd Exons, GnomAd Genomes, etc., in people from different ethnicities), the aminoacid change promoted by this missense variant is practically synonymous for both amino acids residues are polar uncharged (at physiological pH), conserving the hydroxyl group in the side chain of this amino acid, basically having absent to little impact in the CFTR protein. Also, there is another missense variant in the same nucleotide position which has been classified as having uncertain significance (NM_000492.4(CFTR):c.1052C>T; p.Thr351Ile). Besides, prediction tools do not fully agree when predicting the deleteriousness of this variant. Therefore, the controversial data existing to date regarding this variant leads to the classification of uncertain significance. Brief Medical History: the patient was diagnosed with NBS and treated with pancreatic enzymes until the age of 2-3 y.o. The mother decided to stop giving any medication. Since then, the patient presented normal thrive and growth, normal stature, and was eutrophic throughout her life, which would not be expected given the patient's genotype. The patient is now 22 y.o. and has no history of chronic lung infections nor exacerbations or any other features compatible with Cystic Fibrosis. Sweat chloride tests have always been within borderline range (30-59 mM). Also, the patient is pancreatic-sufficient. In January 2020, the patient provided stool samples. Fecal elastase-1 levels in feces samples are within the normal range of the assay, which is a biomarker of pancreatic exocrine sufficiency. Other biochemical and hematological measurements to verify liver function were also normal throughout the patient's life. -

Jan 12, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change replaces threonine, which is neutral and polar, with serine, which is neutral and polar, at codon 351 of the CFTR protein (p.Thr351Ser). This variant is present in population databases (rs1800086, gnomAD 0.07%). This missense change has been observed in individual(s) with pancreatitis, congenital absence of the vas deferens (CAVD), and mild or atypical cysitic fibrosis (PMID: 2395135, 9272157, 15858154, 16128988, 23670503). ClinVar contains an entry for this variant (Variation ID: 53174). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt CFTR protein function with a positive predictive value of 95%. 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. -

not provided Uncertain:5
Feb 19, 2021
Quest Diagnostics Nichols Institute San Juan Capistrano
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Oct 01, 2023
CeGaT Center for Human Genetics Tuebingen
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Apr 18, 2023
Mayo Clinic Laboratories, Mayo Clinic
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

PP3, PM2 -

Feb 22, 2018
Eurofins Ntd Llc (ga)
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Feb 12, 2024
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The CFTR c.1052C>G; p.Thr351Ser variant (rs1800086) is reported in the literature in individuals affected with cystic fibrosis (Schrijver 2005) or a CFTR-related disorder (CFTR-RD; de Cid 2010, Larriba 2005, Masson 2013). While a few CFTR-RD patients also carried a pathogenic CFTR variant (Masson 2013), the p.Thr351Ser variant has been reported on the same chromosome as other CFTR variants, so the contribution to disease is uncertain (Bienvenu 2010, Dal'Maso 2013, Trujillano 2013). This variant is reported in ClinVar (Variant ID: 53174). It is found in the general population with an overall allele frequency of 0.017% (48/282554 alleles) in the Genome Aggregation Database (v2.1.1). In vitro functional analyses showed no significant difference in splicing, protein synthesis/folding or chloride secretion compared to wildtype (Bergougnoux 2023). Computational analyses predict that this variant is deleterious (REVEL: 0.773). Due to conflicting information, the clinical significance of the p.Thr351Ser variant is uncertain at this time. References: Bergougnoux A et al. The multi-faceted nature of 15 CFTR exonic variations: Impact on their functional classification and perspectives for therapy. J Cyst Fibros. 2023 May;22(3):515-524. PMID: 36567205. Bienvenu T et al. Cystic fibrosis transmembrane conductance regulator channel dysfunction in non-cystic fibrosis bronchiectasis. Am J Respir Crit Care Med. 2010 May 15;181(10):1078-84. PMID: 20167849. Dal'Maso VB et al. Diagnostic contribution of molecular analysis of the cystic fibrosis transmembrane conductance regulator gene in patients suspected of having mild or atypical cystic fibrosis. J Bras Pneumol. 2013 Mar-Apr;39(2):181-9. PMID: 23670503. de Cid R et al. Independent contribution of common CFTR variants to chronic pancreatitis. Pancreas. 2010 Mar;39(2):209-15. PMID: 19812525. Larriba S et al. Molecular evaluation of CFTR sequence variants in male infertility of testicular origin. Int J Androl. 2005 Oct;28(5):284-90. PMID: 16128988. Masson E et al. A conservative assessment of the major genetic causes of idiopathic chronic pancreatitis: data from a comprehensive analysis of PRSS1, SPINK1, CTRC and CFTR genes in 253 young French patients. PLoS One. 2013 Aug;8(8):e73522. PMID: 23951356. Schrijver I et al. Diagnostic testing by CFTR gene mutation analysis in a large group of Hispanics: novel mutations and assessment of a population-specific mutation spectrum. J Mol Diagn. 2005 May;7(2):289-99. PMID: 15858154. Trujillano D et al. Next generation diagnostics of cystic fibrosis and CFTR-related disorders by targeted multiplex high-coverage resequencing of CFTR. J Med Genet. 2013 Jul;50(7):455-62. PMID: 23687349. -

CFTR-related disorder Pathogenic:1Uncertain:1Benign:1
Apr 27, 2017
Illumina Laboratory Services, Illumina
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

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. The evidence from the literature, in combination with allele frequency data from public databases where available, was sufficient to rule this variant out of causing disease. Therefore, this variant is classified as benign. -

May 28, 2020
Genome Diagnostics Laboratory, The Hospital for Sick Children
Significance: Likely pathogenic
Review Status: flagged submission
Collection Method: clinical testing

- -

Aug 19, 2024
PreventionGenetics, part of Exact Sciences
Significance: Uncertain significance
Review Status: no assertion criteria provided
Collection Method: clinical testing

The CFTR c.1052C>G variant is predicted to result in the amino acid substitution p.Thr351Ser. This variant has been reported in the heterozygous state in an individual with idiopathic chronic pancreatitis, an individual with CBAVD, and in an individual with clinical manifestations consistent with the spectrum of CF (Table S1, Masson. 2013. PubMed ID: 23951356; Larriba et al. 2005 PubMed ID: 16128988; Schrijver et al. 2005. PubMed ID: 15858154). This variant has also been reported in the compound heterozygous state with a p.Phe508del variant in an individual with CBAVD (Doerk et al. 1997. Table 3 PubMed ID: 9272157) and in the homozygous state (and in cis with another CFTR variant) in an individual with a CFTR-related disorder ( Table S3, Trujillano. 2013. PubMed ID: 23687349). In one individual with CF, this variant was one of three identified, and was in cis with a p.Phe508del variant (Dal'Maso et al. 2013 Table 3 PubMed ID: 23670503). To our knowledge, no functional or family studies are available to confirm the pathogenicity of the c.1052C>G change. This variant is reported in 0.068% of alleles in individuals of Ashkenazi Jewish descent in gnomAD. At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

not specified Uncertain:1
Jan 13, 2025
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Variant summary: CFTR c.1052C>G (p.Thr351Ser) results in a conservative amino acid change located in the ABC transporter type 1, transmembrane domain (IPR036640) of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 0.00019 in 251542 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in CFTR causing Cystic Fibrosis (0.00019 vs 0.013), allowing no conclusion about variant significance. c.1052C>G has been reported in the literature in individuals affected with Cystic Fibrosis, CBAVD, chronic pancreatitis and diffuse bronchiectasis, without strong evidence of causality (Mercier_1993, Dork_1997, Schrijver_2005, Bienvenu_2010, de Cid_2010, Dal Maso_2013, Masson_2013, Trujillano_2013, Grangeia_2018, Rispoli_2020, da Silva Filho_2021, Dermine_2024). These reports do not provide unequivocal conclusions about association of the variant with Cystic Fibrosis. At-least two co-occurrences in cis with other pathogenic variants have been reported (e.g. CFTR c.3484C>T, p.Arg1162X; CFTR c.1521_1523del, p.Phe508del) (Mercier_1993, Dal Maso_2013), providing supporting evidence for a benign role. One of these reports was in an obligate carrier father of an individual with CF (in cis with p.Arg1162X, Mercier_1993) while the other was in an individual reportedly affected with CF who harbored a non-informative genotype attributed to a synonymous variant (p.Pro1290=) in trans (in cis with p.Phe508del, Del Maso_2013). At least two publications report experimental evidence evaluating an impact on protein function (Bergougnoux_2023, Bihler_2024). The variant did not show any deleterious impact on mRNA or protein expression and Western blot results were not suggestive of a folding defect. However, the most pronounced variant effect resulted in approximately 46% of normal chloride channel conductance relative to wild type (e.g. Bihler_2024). The following publications have been ascertained in the context of this evaluation (PMID: 36567205, 20167849, 38388235, 33572515, 23670503, 38657903, 20059485, 9272157, 18716917, 29589582, 16128988, 23951356, 8477260, 25735457, 32185651, 15858154, 23687349, 32819855, 19812525). ClinVar contains an entry for this variant (Variation ID: 53174). Based on the evidence outlined above, the variant was classified as uncertain significance. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.57
BayesDel_addAF
Uncertain
0.092
D
BayesDel_noAF
Pathogenic
0.20
CADD
Uncertain
25
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.68
D;.;.;T;.
Eigen
Pathogenic
0.69
Eigen_PC
Pathogenic
0.70
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.96
D;D;D;D;D
M_CAP
Pathogenic
0.69
D
MetaRNN
Uncertain
0.54
D;D;D;D;D
MetaSVM
Uncertain
0.65
D
MutationAssessor
Uncertain
2.3
M;.;.;.;M
PrimateAI
Uncertain
0.64
T
PROVEAN
Benign
-1.1
N;.;.;N;.
REVEL
Pathogenic
0.77
Sift
Uncertain
0.0070
D;.;.;D;.
Sift4G
Pathogenic
0.0
D;.;.;D;.
Polyphen
0.95
P;.;.;.;.
Vest4
0.85
MutPred
0.82
Gain of helix (P = 0.132);Gain of helix (P = 0.132);Gain of helix (P = 0.132);.;Gain of helix (P = 0.132);
MVP
0.99
MPC
0.0052
ClinPred
0.21
T
GERP RS
5.3
Varity_R
0.80
gMVP
0.83

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.010
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

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs1800086; hg19: chr7-117180336; API