rs397508700

chr7-117531047-C-A

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.422C>A(p.Ala141Asp) variant causes a missense change. The variant allele was found at a frequency of 0.00000124 in 1,613,608 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). Synonymous variant affecting the same amino acid position (i.e. A141A) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: CFTR NM_000492.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:1 O:1
• Conservation: PhyloP100: 5.80

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 hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 13 uncertain in NM_000492.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.979
• PP5: Variant 7-117531047-C-A is Pathogenic according to our data. Variant chr7-117531047-C-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 53924.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=2, Uncertain_significance=1, not_provided=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CFTR	NM_000492.4	c.422C>A	p.Ala141Asp	missense_variant	4/27	ENST00000003084.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CFTR	ENST00000003084.11	c.422C>A	p.Ala141Asp	missense_variant	4/27	1	NM_000492.4	P2

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152120 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: 0.000208

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461488 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727018

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152120 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74296

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.000208

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2 Uncertain:1 Other:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Cystic fibrosis Pathogenic:2 Uncertain:1 Other:1

not provided, no classification provided	literature only	ClinVar Staff, National Center for Biotechnology Information (NCBI)	-	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Jan 25, 2024	The p.A141D variant (also known as c.422C>A), located in coding exon 4 of the CFTR gene, results from a C to A substitution at nucleotide position 422. The alanine at codon 141 is replaced by aspartic acid, an amino acid with dissimilar properties. This alteration has been identified in multiple individuals diagnosed with cystic fibrosis (Gouya L et al. Hum Mutat, 1997;10:86-7; Kambouris M et al. Eur J Pediatr, 2000 May;159:303-9; Petrova NV et al. Genes (Basel), 2020 May;11:). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, the clinical significance of this alteration remains unclear. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Johns Hopkins Genomics, Johns Hopkins University	Oct 04, 2019	This CFTR variant is absent from large population datasets. This variant is present in ClinVar by one submitter, however a classification was not provided. Multiple patients have been reported to carry this variant along with a second disease-causing CFTR variant; in one of these cases the variants were confirmed to be on opposite chromosomes (in trans). Of two bioinformatics tools queried, one predicts that the substitution would be possibly damaging, while the second predicts that it would be tolerated. The alanine residue at this position is highly evolutionarily conserved across most species assessed. We consider this variant likely pathogenic. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jan 03, 2024	This sequence change replaces alanine, which is neutral and non-polar, with aspartic acid, which is acidic and polar, at codon 141 of the CFTR protein (p.Ala141Asp). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with cystic fibrosis (PMID: 9222768, 30548586, 32429104). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 53924). 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 with a positive predictive value of 80%. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.96
BayesDel_addAF	Pathogenic	0.41	D
BayesDel_noAF	Pathogenic	0.35
Cadd	Uncertain	25
Dann	Uncertain	1.0
DEOGEN2	Uncertain	0.78	D;.;.;T;.
Eigen	Uncertain	0.61
Eigen_PC	Uncertain	0.65
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.93	D;D;D;D;D
M_CAP	Pathogenic	0.78	D
MetaRNN	Pathogenic	0.98	D;D;D;D;D
MetaSVM	Uncertain	0.60	D
MutationAssessor	Uncertain	2.0	M;.;.;.;M
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.69	T
PROVEAN	Benign	-2.3	N;.;.;N;.
REVEL	Pathogenic	0.77
Sift	Benign	0.063	T;.;.;T;.
Sift4G	Pathogenic	0.0	D;.;.;D;.
Polyphen		0.84	P;.;.;.;.
Vest4		0.97
MutPred		0.89		Gain of relative solvent accessibility (P = 0.1259);Gain of relative solvent accessibility (P = 0.1259);Gain of relative solvent accessibility (P = 0.1259);Gain of relative solvent accessibility (P = 0.1259);Gain of relative solvent accessibility (P = 0.1259);
MVP		1.0
MPC		0.0042
ClinPred		0.91	D
GERP RS		5.7
Varity_R		0.93
gMVP		0.99

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: rs397508700; hg19: chr7-117171101;