NM_000492.4:c.1522_1524delTTT

Variant names:

• chr7-117559592-CTTT-C
• rs121909001
• NM_000492.4:c.1522_1524delTTT

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM1 PM2 PM4_Supporting PP5_Moderate

The NM_000492.4(CFTR):​c.1522_1524delTTT​(p.Phe508del) variant causes a conservative inframe deletion change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★). Synonymous variant affecting the same amino acid position (i.e. F508F) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: CFTR NM_000492.4 conservative_inframe_deletion
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 7.54
• Publications: 16 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-AS1 (HGNC:40144): (CFTR antisense RNA 1)

ACMG classification

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

• PM1: In a hotspot region, there are 22 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 19 uncertain in NM_000492.4
• PM2: Very rare variant in population databases, with high coverage
• PM4: Nonframeshift variant in NON repetitive region in NM_000492.4. Strenght limited to Supporting due to length of the change: 1aa.
• PP5: Variant 7-117559592-CTTT-C is Pathogenic according to our data. Variant chr7-117559592-CTTT-C is described in ClinVar as Pathogenic. ClinVar VariationId is 4072070.Status of the report is criteria_provided_single_submitter, 1 stars.

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.1522_1524delTTT	p.Phe508del	conservative_inframe_deletion	Exon 11 of 27	NP_000483.3
	CFTR-AS1	NR_149084.1		n.221+1138_221+1140delAAA		intron	N/A

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CFTR	ENST00000003084.11	TSL:1 MANE Select	c.1522_1524delTTT	p.Phe508del	conservative_inframe_deletion	Exon 11 of 27	ENSP00000003084.6
	CFTR	ENST00000699602.1		c.1522_1524delTTT	p.Phe508del	conservative_inframe_deletion	Exon 11 of 27	ENSP00000514471.1
	CFTR	ENST00000426809.5	TSL:5	c.1432_1434delTTT	p.Phe478del	conservative_inframe_deletion	Exon 10 of 26	ENSP00000389119.1

Frequencies

GnomAD3 genomes Cov.: 32

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Cystic fibrosis Pathogenic:1

Jun 28, 2025

Immunogenetics and Transplant Biology Service, University Hospital "Città della Salute e della Scienza di Torino"

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		7.5

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

Other links and lift over

dbSNP: rs121909001; hg19: chr7-117199646;