20-49393138-G-A

Position:

• chr20-49393138-G-A

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_004975.4(KCNB1):​c.568-18146C>T variant causes a intron 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.

• Frequency: Genomes: not found (cov: 31)
• Consequence: KCNB1 NM_004975.4 intron
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.0550

Genes affected

KCNB1 (HGNC:6231): (potassium voltage-gated channel subfamily B member 1) Voltage-gated potassium (Kv) channels represent the most complex class of voltage-gated ion channels from both functional and structural standpoints. Their diverse functions include regulating neurotransmitter release, heart rate, insulin secretion, neuronal excitability, epithelial electrolyte transport, smooth muscle contraction, and cell volume. Four sequence-related potassium channel genes - shaker, shaw, shab, and shal - have been identified in Drosophila, and each has been shown to have human homolog(s). This gene encodes a member of the potassium channel, voltage-gated, shab-related subfamily. This member is a delayed rectifier potassium channel and its activity is modulated by some other family members. [provided by RefSeq, Jul 2008]

(HGNC:):

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.72).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KCNB1	NM_004975.4	c.568-18146C>T		intron_variant		ENST00000371741.6
LOC105372649	XR_001754659.2	n.1202-33514G>A		intron_variant, non_coding_transcript_variant
KCNB1	XM_011528799.3	c.568-18146C>T		intron_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KCNB1	ENST00000371741.6	c.568-18146C>T		intron_variant		1	NM_004975.4	P1
KCNB1	ENST00000635465.1	c.568-18146C>T		intron_variant		1		P1
	ENST00000637341.1	n.207-29954G>A		intron_variant, non_coding_transcript_variant		5
KCNB1	ENST00000635878.1	c.96+88776C>T		intron_variant		5

Frequencies

GnomAD3 genomes Cov.: 31

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 31

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.72
CADD	Benign	12
DANN	Benign	0.81

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

Publications

LitVar

Other links and lift over

dbSNP: rs6125642; hg19: chr20-48009675;