NM_000492.4:c.3084G>T

Variant names:

• chr7-117610614-G-T
• rs200553511
• NM_000492.4:c.3084G>T

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM1 PM2 PP2

The NM_000492.4(CFTR):​c.3084G>T​(p.Met1028Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,370 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as not provided (no stars). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Uncertain significance in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M1028R) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: CFTR NM_000492.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1 O:1
• Conservation: PhyloP100: -0.889
• Publications: 6 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)

ENSG00000083622 (HGNC:40145):

ACMG classification

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

• PM1: In a hotspot region, there are 8 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 18 uncertain in NM_000492.4
• PM2: Very rare variant in population databases, with high coverage
• 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.

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.3084G>T	p.Met1028Ile	missense	Exon 19 of 27	NP_000483.3
	CFTR-AS2	NR_199597.1		n.177+5615C>A		intron	N/A

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CFTR	ENST00000003084.11	TSL:1 MANE Select	c.3084G>T	p.Met1028Ile	missense	Exon 19 of 27	ENSP00000003084.6
	CFTR	ENST00000699602.1		c.3084G>T	p.Met1028Ile	missense	Exon 19 of 27	ENSP00000514471.1
	CFTR	ENST00000426809.5	TSL:5	c.2994G>T	p.Met998Ile	missense	Exon 18 of 26	ENSP00000389119.1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461370 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 726992

African (AFR) AF: 0.00 AC: 0 AN: 33452

American (AMR) AF: 0.00 AC: 0 AN: 44664

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26116

East Asian (EAS) AF: 0.00 AC: 0 AN: 39660

South Asian (SAS) AF: 0.00 AC: 0 AN: 86252

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53380

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5762

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1111728

Other (OTH) AF: 0.00 AC: 0 AN: 60356

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1 Other:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Jul 16, 2025

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: CFTR c.3084G>T (p.Met1028Ile) results in a conservative amino acid change in the encoded protein sequence. Algorithms developed to predict the effect of missense changes on protein structure and function all suggest that this variant is likely to be tolerated. The variant was absent in 250970 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.3084G>T has been observed in the heterozygous state in at least one individual affected with Cystic Fibrosis (Onay_1998). These report(s) do not provide unequivocal conclusions about association of the variant with Cystic Fibrosis. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication have been ascertained in the context of this evaluation (PMID: 9521595). ClinVar contains an entry for this variant (Variation ID: 53648). Based on the evidence outlined above, the variant was classified as uncertain significance.

Cystic fibrosis Other:1

ClinVar Staff, National Center for Biotechnology Information (NCBI)

Significance: not provided

Review Status: no classification provided

Collection Method: literature only

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.12
BayesDel_addAF	Uncertain	0.032	T
BayesDel_noAF	Benign	-0.19
CADD	Benign	0.0020
DANN	Benign	0.71
DEOGEN2	Uncertain	0.45	T
Eigen	Benign	-2.2
Eigen_PC	Benign	-2.4
FATHMM_MKL	Benign	0.053	N
LIST_S2	Benign	0.73	T
M_CAP	Uncertain	0.10	D
MetaRNN	Uncertain	0.65	D
MetaSVM	Benign	-0.54	T
MutationAssessor	Benign	0.47	N
PhyloP100		-0.89
PrimateAI	Benign	0.43	T
PROVEAN	Benign	0.090	N
REVEL	Uncertain	0.48
Sift	Benign	0.46	T
Sift4G	Benign	1.0	T
Polyphen		0.0	B
Vest4		0.72
MutPred		0.88		Loss of methylation at R1030 (P = 0.0745)
MVP		0.94
MPC		0.0039
ClinPred		0.21	T
GERP RS		-12
Varity_R		0.13
gMVP		0.85
Mutation Taster		=45/55	disease causing

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

Other links and lift over

dbSNP: rs200553511; hg19: chr7-117250668;