chr7-117540157-C-T

Position:

• chr7-117540157-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP6

The NM_000492.4(CFTR):​c.927C>T​(p.Ala309=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000226 in 1,461,388 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.000023 (0 hom.)
• Consequence: CFTR NM_000492.4 synonymous
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:3
• Conservation: PhyloP100: 0.572

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 Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP6: Variant 7-117540157-C-T is Benign according to our data. Variant chr7-117540157-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 256258.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=2, Uncertain_significance=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CFTR	NM_000492.4	c.927C>T	p.Ala309=	synonymous_variant	8/27	ENST00000003084.11	NP_000483.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CFTR	ENST00000003084.11	c.927C>T	p.Ala309=	synonymous_variant	8/27	1	NM_000492.4	ENSP00000003084	P2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.0000119 AC: 3 AN: 251120 Hom.: 0 AF XY: 0.00000737 AC XY: 1 AN XY: 135744

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.000163

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000226 AC: 33 AN: 1461388 Hom.: 0 Cov.: 31 AF XY: 0.0000206 AC XY: 15 AN XY: 727004

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.000756

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000180

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:3

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Cystic fibrosis Uncertain:1 Benign:2

Likely benign, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 31, 2024	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Apr 18, 2022	The c.927C>T variant (also known as p.A309A), located in coding exon 8 of the CFTR gene, results from a C to T substitution at nucleotide position 927. This nucleotide substitution does not change the alanine at codon 309. This alteration has been identified in an individual diagnosed with pancreatitis (Lee JH et al. Hum Mol Genet, 2003 Sep;12:2321-32). This nucleotide position is not well conserved in available vertebrate species. In silico splice site analysis predicts that this alteration may result in the creation or strengthening of a novel splice acceptor site. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Likely benign, no assertion criteria provided	clinical testing	Natera, Inc.	Sep 16, 2020	- -

not specified Benign:1

Likely benign, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.27
CADD	Benign	16
DANN	Benign	0.61

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.32		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.32		Position offset: 14

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

Publications

LitVar

Other links and lift over

dbSNP: rs1800084; hg19: chr7-117180211;