rs766541549

chr7-117592422-T-Cchr7-117592422-T-G

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 4P and 1B. PM1 PM2 BP4

The NM_000492.4(CFTR):c.2255T>C(p.Ile752Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I752S) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: CFTR NM_000492.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 2.84

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 3 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 11 uncertain in NM_000492.4
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.2687285).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CFTR	NM_000492.4	c.2255T>C	p.Ile752Thr	missense_variant	14/27	ENST00000003084.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CFTR	ENST00000003084.11	c.2255T>C	p.Ile752Thr	missense_variant	14/27	1	NM_000492.4	P2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.092
BayesDel_addAF	Uncertain	0.11	D
BayesDel_noAF	Uncertain	-0.080
Cadd	Benign	16
Dann	Benign	0.54
DEOGEN2	Uncertain	0.45	T;.;T;.
Eigen	Benign	-0.61
Eigen_PC	Benign	-0.43
FATHMM_MKL	Uncertain	0.86	D
LIST_S2	Benign	0.77	T;T;T;T
M_CAP	Uncertain	0.097	D
MetaRNN	Benign	0.27	T;T;T;T
MetaSVM	Uncertain	-0.21	T
MutationAssessor	Benign	0.0	N;.;.;.
MutationTaster	Benign	0.98	N;N
PrimateAI	Benign	0.38	T
PROVEAN	Benign	1.4	N;.;N;.
REVEL	Uncertain	0.33
Sift	Benign	0.21	T;.;T;.
Sift4G	Uncertain	0.027	D;.;D;.
Polyphen		0.0010	B;.;.;.
Vest4		0.20
MutPred		0.41		Loss of stability (P = 0.002);.;.;.;
MVP		0.96
MPC		0.0037
ClinPred		0.39	T
GERP RS		4.7
Varity_R		0.31
gMVP		0.12

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs766541549; hg19: chr7-117232476;