12-21766203-C-T

Variant names:

• chr12-21766203-C-T
• rs780436709
• NM_004982.4:c.795G>A
• KCNJ8 p.Leu265Leu

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 2P and 3B. PM2 BP4_Moderate BP7

The NM_004982.4(KCNJ8):​c.795G>A​(p.Leu265Leu) variant causes a synonymous 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. Synonymous variant affecting the same amino acid position (i.e. L265L) has been classified as Benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: KCNJ8 NM_004982.4 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.409
• Publications: 0 publications found

Genes affected

KCNJ8 (HGNC:6269): (potassium inwardly rectifying channel subfamily J member 8) Potassium channels are present in most mammalian cells, where they participate in a wide range of physiologic responses. The protein encoded by this gene is an integral membrane protein and inward-rectifier type potassium channel. The encoded protein, which has a greater tendency to allow potassium to flow into a cell rather than out of a cell, is controlled by G-proteins. Defects in this gene may be a cause of J-wave syndromes and sudden infant death syndrome (SIDS). [provided by RefSeq, May 2012]

KCNJ8 Gene-Disease associations (from GenCC):

• hypertrichotic osteochondrodysplasia Cantu type

  Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae)
• Brugada syndrome

  Inheritance: Unknown Classification: LIMITED Submitted by: Genomics England PanelApp
• Brugada syndrome 1

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

KCNJ8-AS1 (HGNC:58193):

ACMG classification

Our verdict: Likely_benign. The variant received -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.45).
• BP7: Synonymous conserved (PhyloP=0.409 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_004982.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNJ8	NM_004982.4	MANE Select	c.795G>A	p.Leu265Leu	synonymous	Exon 3 of 3	NP_004973.1	Q15842

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNJ8	ENST00000240662.3	TSL:1 MANE Select	c.795G>A	p.Leu265Leu	synonymous	Exon 3 of 3	ENSP00000240662.2	Q15842
	KCNJ8	ENST00000859815.1		c.933G>A	p.Leu311Leu	synonymous	Exon 4 of 4	ENSP00000529874.1
	KCNJ8	ENST00000951731.1		c.933G>A	p.Leu311Leu	synonymous	Exon 5 of 5	ENSP00000621790.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00 AC: 0 AN: 251202 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.45
CADD	Benign	5.1
DANN	Benign	0.85
PhyloP100		0.41

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

dbSNP: rs780436709;

hg19: chr12-21919137;