12-70367041-G-A

Position:

• chr12-70367041-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_014505.6(KCNMB4):​c.307G>A​(p.Asp103Asn) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: not found (cov: 31)
• Consequence: KCNMB4 NM_014505.6 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 8.58

Genes affected

KCNMB4 (HGNC:6289): (potassium calcium-activated channel subfamily M regulatory beta subunit 4) MaxiK channels are large conductance, voltage and calcium-sensitive potassium channels which are fundamental to the control of smooth muscle tone and neuronal excitability. MaxiK channels can be formed by 2 subunits: the pore-forming alpha subunit and the modulatory beta subunit. The protein encoded by this gene is an auxiliary beta subunit which slows activation kinetics, leads to steeper calcium sensitivity, and shifts the voltage range of current activation to more negative potentials than does the beta 1 subunit. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
KCNMB4	NM_014505.6	c.307G>A	p.Asp103Asn	missense_variant	1/3	ENST00000258111.5	NP_055320.4
KCNMB4	XM_011538188.3	c.307G>A	p.Asp103Asn	missense_variant	1/3		XP_011536490.1
KCNMB4	XM_047428701.1	c.307G>A	p.Asp103Asn	missense_variant	1/3		XP_047284657.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
KCNMB4	ENST00000258111.5	c.307G>A	p.Asp103Asn	missense_variant	1/3	1	NM_014505.6	ENSP00000258111.4

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Oct 24, 2024

The c.307G>A (p.D103N) alteration is located in exon 1 (coding exon 1) of the KCNMB4 gene. This alteration results from a G to A substitution at nucleotide position 307, causing the aspartic acid (D) at amino acid position 103 to be replaced by an asparagine (N). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_addAF	Benign	-0.24	T
BayesDel_noAF	Benign	-0.58
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Benign	0.065	T
Eigen	Benign	0.16
Eigen_PC	Benign	0.15
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Uncertain	0.89	D
M_CAP	Benign	0.029	D
MetaRNN	Uncertain	0.43	T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	0.56	N
PrimateAI	Uncertain	0.74	T
PROVEAN	Benign	0.12	N
REVEL	Benign	0.24
Sift	Benign	0.81	T
Sift4G	Benign	0.35	T
Polyphen		1.0	D
Vest4		0.52
MutPred		0.47		Gain of catalytic residue at L107 (P = 0.0022);
MVP		0.23
MPC		2.2
ClinPred		0.74	D
GERP RS		2.5
Varity_R		0.43
gMVP		0.80

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr12-70760821;