7-117590394-C-T

Variant names:

• chr7-117590394-C-T
• rs121908758
• NM_000492.4:c.1721C>T

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PM1 PM2 PM5 PP2 PP3_Strong

The NM_000492.4(CFTR):​c.1721C>T​(p.Pro574Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000689 in 1,451,150 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. P574H) has been classified as Pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: CFTR NM_000492.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.31
• Publications: 0 publications found

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]

CFTR Gene-Disease associations (from GenCC):

• cystic fibrosis

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), Myriad Women’s Health, Orphanet
• congenital bilateral absence of vas deferens

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• hereditary chronic pancreatitis

  Inheritance: AD Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Pathogenic. The variant received 11 ACMG points.

• PM1: In a hotspot region, there are 10 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 22 uncertain in NM_000492.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr7-117590394-C-A is described in ClinVar as Pathogenic. ClinVar VariationId is 7119.Status of the report is reviewed_by_expert_panel, 3 stars.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 197 curated pathogenic missense variants (we use a threshold of 10). The gene has 46 curated benign missense variants. Gene score misZ: -3.1397 (below the threshold of 3.09). Trascript score misZ: -1.0868 (below the threshold of 3.09). GenCC associations: The gene is linked to hereditary chronic pancreatitis, cystic fibrosis, congenital bilateral absence of vas deferens.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.987

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000492.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CFTR	NM_000492.4	MANE Select	c.1721C>T	p.Pro574Leu	missense	Exon 13 of 27	NP_000483.3

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CFTR	ENST00000003084.11	TSL:1 MANE Select	c.1721C>T	p.Pro574Leu	missense	Exon 13 of 27	ENSP00000003084.6
	CFTR	ENST00000699602.1		c.1721C>T	p.Pro574Leu	missense	Exon 13 of 27	ENSP00000514471.1
	CFTR	ENST00000426809.5	TSL:5	c.1631C>T	p.Pro544Leu	missense	Exon 12 of 26	ENSP00000389119.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.89e-7 AC: 1 AN: 1451150 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 721802

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33244

American (AMR) AF: 0.00 AC: 0 AN: 44382

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25624

East Asian (EAS) AF: 0.00 AC: 0 AN: 39368

South Asian (SAS) AF: 0.00 AC: 0 AN: 86084

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52620

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5702

European-Non Finnish (NFE) AF: 9.05e-7 AC: 1 AN: 1104428

Other (OTH) AF: 0.00 AC: 0 AN: 59698

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Cystic fibrosis Uncertain:1

May 12, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.P574L variant (also known as c.1721C>T), located in coding exon 13 of the CFTR gene, results from a C to T substitution at nucleotide position 1721. The proline at codon 574 is replaced by leucine, an amino acid with similar properties. 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 variant remains unclear.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.79
BayesDel_addAF	Pathogenic	0.52	D
BayesDel_noAF	Pathogenic	0.51
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.96	D
Eigen	Pathogenic	0.90
Eigen_PC	Pathogenic	0.81
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.96	D
M_CAP	Pathogenic	0.71	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.4	M
PhyloP100		7.3
PrimateAI	Uncertain	0.76	T
PROVEAN	Pathogenic	-6.6	D
REVEL	Pathogenic	0.96
Sift	Benign	0.040	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.92
MutPred		0.92		Loss of phosphorylation at Y577 (P = 0.0963)
MVP		1.0
MPC		0.017
ClinPred		1.0	D
GERP RS		4.8
Varity_R		0.90
gMVP		0.98
Mutation Taster		=13/87	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.27		Details are displayed if max score is > 0.2
DS_AL_spliceai		0.27		Position offset: -41

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs121908758; hg19: chr7-117230448; COSMIC: COSV50040509; COSMIC: COSV50040509;