chr7-117531035-T-C

Variant names:

• chr7-117531035-T-C
• rs397508674
• NM_000492.4:c.410T>C

Variant summary

Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PM1 PM2 PP3_Strong PP5

The NM_000492.4(CFTR):​c.410T>C​(p.Leu137Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,156 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 Conflicting classifications of pathogenicity (no stars).

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: CFTR NM_000492.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:4 U:2
• Conservation: PhyloP100: 7.61

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 Likely_pathogenic. Variant got 9 ACMG points.

• PM1: In a domain ABC transmembrane type-1 1 (size 284) in uniprot entity CFTR_HUMAN there are 65 pathogenic changes around while only 10 benign (87%) in NM_000492.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.991
• PP5: Variant 7-117531035-T-C is Pathogenic according to our data. Variant chr7-117531035-T-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 582298.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=3, Uncertain_significance=2, Pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CFTR	NM_000492.4	c.410T>C	p.Leu137Pro	missense_variant	Exon 4 of 27	ENST00000003084.11	NP_000483.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CFTR	ENST00000003084.11	c.410T>C	p.Leu137Pro	missense_variant	Exon 4 of 27	1	NM_000492.4	ENSP00000003084.6

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152156 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: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 31

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152156 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74322

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:4 Uncertain:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Cystic fibrosis Pathogenic:4 Uncertain:2

Jul 22, 2021

Genome-Nilou Lab

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Feb 05, 2025

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

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: CFTR c.410T>C (p.Leu137Pro) results in a non-conservative amino acid change located in the ABC transporter type 1, transmembrane domain (IPR011527) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant was absent in 250744 control chromosomes (gnomAD). c.410T>C has been reported in the literature in individuals affected with Cystic Fibrosis (e.g., Kanavakis_2003, daSilvaFilho_2021). These reports do not provide unequivocal conclusions about association of the variant with Cystic Fibrosis. Publications report experimental evidence evaluating an impact on protein function. The most pronounced variant effect resulted in approximately 2% 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: 12752573, 19236881, 32819855, 38388235). ClinVar contains an entry for this variant (Variation ID: 582298). Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Sep 05, 2022

Institute of Human Genetics, University of Leipzig Medical Center

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: curation

This variant was identified in 1 patient 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, PM5_STR, PP3, PP4 -

Aug 12, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces leucine with proline at codon 137 of the CFTR protein (p.Leu137Pro). The leucine residue is moderately conserved and there is a moderate physicochemical difference between leucine and proline. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals affected with CFTR-related conditions. ClinVar contains an entry for this variant (Variation ID: 582298). 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. Experimental studies are conflicting or provide insufficient evidence to determine the effect of this variant on CFTR function (PMID: 19236881). 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. -

Nov 09, 2024

Ambry Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.L137P variant (also known as c.410T>C), located in coding exon 4 of the CFTR gene, results from a T to C substitution at nucleotide position 410. The leucine at codon 137 is replaced by proline, an amino acid with similar properties. In a cohort of 437 unrelated Greek individuals with cystic fibrosis, this variant was detected twice (Kanavakis E et al. Clin. Genet., 2003 May;63:400-9). This variant has been identified in conjunction with another CFTR variant in an individual with features consistent with cystic fibrosis (Ambry internal data). In an assay testing CFTR function, this variant showed a functionally abnormal result (Bihler H et al. J Cyst Fibros, 2024 Jul;23:664-675). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). Based on the majority of available evidence to date, this variant is likely to be pathogenic. -

Nov 05, 2018

Mendelics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.94
BayesDel_addAF	Pathogenic	0.47	D
BayesDel_noAF	Pathogenic	0.44
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.93	D;.;.;D;.
Eigen	Uncertain	0.65
Eigen_PC	Uncertain	0.61
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.92	D;D;D;D;D
M_CAP	Pathogenic	0.66	D
MetaRNN	Pathogenic	0.99	D;D;D;D;D
MetaSVM	Pathogenic	0.91	D
MutationAssessor	Uncertain	2.5	M;.;.;.;M
PrimateAI	Uncertain	0.63	T
PROVEAN	Uncertain	-4.2	D;.;.;D;.
REVEL	Pathogenic	0.89
Sift	Uncertain	0.0020	D;.;.;D;.
Sift4G	Pathogenic	0.0	D;.;.;D;.
Polyphen		1.0	D;.;.;.;.
Vest4		0.98
MutPred		0.94		Loss of catalytic residue at L137 (P = 0.0245);Loss of catalytic residue at L137 (P = 0.0245);Loss of catalytic residue at L137 (P = 0.0245);Loss of catalytic residue at L137 (P = 0.0245);Loss of catalytic residue at L137 (P = 0.0245);
MVP		1.0
MPC		0.012
ClinPred		0.99	D
GERP RS		5.7
Varity_R		0.95
gMVP		0.99

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.060		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: rs397508674; hg19: chr7-117171089;