rs397508754

chr7-117534347-C-Achr7-117534347-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1 PM2 PP3_Strong

The NM_000492.4(CFTR):c.561C>A(p.Asn187Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000021 in 1,429,434 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. N187S) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: CFTR NM_000492.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2 O:1
• Conservation: PhyloP100: 0.654

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 8 ACMG points.

• PM1: In a hotspot region, there are 6 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 10 uncertain in NM_000492.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.967

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CFTR	NM_000492.4	c.561C>A	p.Asn187Lys	missense_variant	5/27	ENST00000003084.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CFTR	ENST00000003084.11	c.561C>A	p.Asn187Lys	missense_variant	5/27	1	NM_000492.4	P2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000210 AC: 3 AN: 1429434 Hom.: 0 Cov.: 25 AF XY: 0.00000280 AC XY: 2 AN XY: 713234

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: 0.0000117

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000185

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000712 Hom.: 0

Bravo AF: 0.00000378

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2 Other:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Cystic fibrosis Uncertain:1 Other:1

Uncertain significance, criteria provided, single submitter	clinical testing	Counsyl	Aug 02, 2017	- -
not provided, no classification provided	literature only	ClinVar Staff, National Center for Biotechnology Information (NCBI)	-	- -

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

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

Nov 19, 2023

Variant summary: CFTR c.561C>A (p.Asn187Lys) 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 allele was found at a frequency of 2.1e-06 in 1429434 control chromosomes (gnomAD v4). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.561C>A has been reported in the literature as a non-informative genotype (heterozygous) in at-least one individual with pancreatitis (example, Arduino_1999 overlapping with Gaia_2002). These report(s) 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: 10668931, 12452372, 36834620). One submitter has cited clinical-significance assessments for this variant to ClinVar after 2014 and has classified the variant as uncertain significance. 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	0.88
BayesDel_addAF	Uncertain	0.11	D
BayesDel_noAF	Uncertain	-0.080
Cadd	Uncertain	24
Dann	Uncertain	1.0
DEOGEN2	Pathogenic	0.85	D;.;.;.
Eigen	Uncertain	0.42
Eigen_PC	Uncertain	0.40
FATHMM_MKL	Uncertain	0.90	D
LIST_S2	Uncertain	0.96	D;D;D;D
M_CAP	Pathogenic	0.85	D
MetaRNN	Pathogenic	0.97	D;D;D;D
MetaSVM	Uncertain	0.61	D
MutationAssessor	Benign	1.8	L;.;.;L
MutationTaster	Benign	1.0	D;D
PrimateAI	Pathogenic	0.79	T
PROVEAN	Uncertain	-2.6	D;.;.;.
REVEL	Pathogenic	0.73
Sift	Uncertain	0.0050	D;.;.;.
Sift4G	Uncertain	0.0040	D;.;.;.
Polyphen		0.99	D;.;.;.
Vest4		0.88
MutPred		0.88		Gain of ubiquitination at N187 (P = 0.023);Gain of ubiquitination at N187 (P = 0.023);Gain of ubiquitination at N187 (P = 0.023);Gain of ubiquitination at N187 (P = 0.023);
MVP		0.97
MPC		0.013
ClinPred		0.97	D
GERP RS		3.7
Varity_R		0.94
gMVP		0.93

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: rs397508754; hg19: chr7-117174401;