rs397508798

Variant names:

• chr7-117504277-AG-A
• rs397508798
• NM_000492.4:c.80delG

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1 PM2

The NM_000492.4(CFTR):​c.80delG​(p.Gly27AspfsTer64) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000686 in 1,458,558 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as not provided (no stars).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: CFTR NM_000492.4 frameshift
• Clinical Significance: not provided no classification provided O:1
• Conservation: PhyloP100: 7.71
• Publications: 1 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: Orphanet, Labcorp Genetics (formerly Invitae), Laboratory for Molecular Medicine, Myriad Women's Health
• 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 10 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 1245 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage

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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CFTR	NM_000492.4	MANE Select	c.80delG	p.Gly27AspfsTer64	frameshift	Exon 2 of 27	NP_000483.3

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CFTR	ENST00000003084.11	TSL:1 MANE Select	c.80delG	p.Gly27AspfsTer64	frameshift	Exon 2 of 27	ENSP00000003084.6	P13569-1
	CFTR	ENST00000546407.1	TSL:1	n.193delG		non_coding_transcript_exon	Exon 3 of 3
	CFTR	ENST00000699602.1		c.80delG	p.Gly27AspfsTer64	frameshift	Exon 2 of 27	ENSP00000514471.1	A0A8V8TNH2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.86e-7 AC: 1 AN: 1458558 Hom.: 0 Cov.: 29 AF XY: 0.00 AC XY: 0 AN XY: 725852

⚠️ 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: 33402

American (AMR) AF: 0.00 AC: 0 AN: 44710

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26088

East Asian (EAS) AF: 0.00 AC: 0 AN: 39612

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86188

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53410

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5750

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1109128

Other (OTH) AF: 0.00 AC: 0 AN: 60270

⚠️ 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

ClinVar submissions

Significance: not provided

Revision: no classification provided

Pathogenic	VUS	Benign	Condition
-	-	-	Cystic fibrosis (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		7.7
Mutation Taster		=1/199	disease causing (fs/PTC)

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

dbSNP: rs397508798;

hg19: chr7-117144331;