NM_000218.3:c.1800G>T

Variant names:

• chr11-2847772-G-T
• rs147091980
• NM_000218.3:c.1800G>T

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_000218.3(KCNQ1):​c.1800G>T​(p.Thr600Thr) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000704 in 1,421,300 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. T600T) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 7.0e-7 (0 hom.)
• Consequence: KCNQ1 NM_000218.3 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -3.42
• Publications: 0 publications found

Genes affected

KCNQ1 (HGNC:6294): (potassium voltage-gated channel subfamily Q member 1) This gene encodes a voltage-gated potassium channel required for repolarization phase of the cardiac action potential. This protein can form heteromultimers with two other potassium channel proteins, KCNE1 and KCNE3. Mutations in this gene are associated with hereditary long QT syndrome 1 (also known as Romano-Ward syndrome), Jervell and Lange-Nielsen syndrome, and familial atrial fibrillation. This gene exhibits tissue-specific imprinting, with preferential expression from the maternal allele in some tissues, and biallelic expression in others. This gene is located in a region of chromosome 11 amongst other imprinted genes that are associated with Beckwith-Wiedemann syndrome (BWS), and itself has been shown to be disrupted by chromosomal rearrangements in patients with BWS. Alternatively spliced transcript variants have been found for this gene. [provided by RefSeq, Aug 2011]

KCNQ1-AS1 (HGNC:42790): (KCNQ1 antisense RNA 1)

ACMG classification

Our verdict: Likely_benign. The variant received -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.84).
• BP7: Synonymous conserved (PhyloP=-3.42 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNQ1	NM_000218.3	c.1800G>T	p.Thr600Thr	synonymous_variant	Exon 16 of 16	ENST00000155840.12	NP_000209.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KCNQ1	ENST00000155840.12	c.1800G>T	p.Thr600Thr	synonymous_variant	Exon 16 of 16	1	NM_000218.3	ENSP00000155840.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 7.04e-7 AC: 1 AN: 1421300 Hom.: 0 Cov.: 31 AF XY: 0.00000142 AC XY: 1 AN XY: 703312

African (AFR) AF: 0.00 AC: 0 AN: 32702

American (AMR) AF: 0.00 AC: 0 AN: 39284

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25434

East Asian (EAS) AF: 0.00 AC: 0 AN: 37624

South Asian (SAS) AF: 0.0000123 AC: 1 AN: 81046

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 49548

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5716

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1091046

Other (OTH) AF: 0.00 AC: 0 AN: 58900

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.84
CADD	Benign	0.059
DANN	Benign	0.85
PhyloP100		-3.4

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: rs147091980; hg19: chr11-2869002;