19-17975173-G-A

Position:

• chr19-17975173-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_001386974.1(KCNN1):​c.484G>A​(p.Ala162Thr) variant causes a missense change. The variant allele was found at a frequency of 0.00000137 in 1,461,470 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: KCNN1 NM_001386974.1 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.53

Genes affected

KCNN1 (HGNC:6290): (potassium calcium-activated channel subfamily N member 1) Action potentials in vertebrate neurons are followed by an afterhyperpolarization (AHP) that may persist for several seconds and may have profound consequences for the firing pattern of the neuron. Each component of the AHP is kinetically distinct and is mediated by different calcium-activated potassium channels. The protein encoded by this gene is activated before membrane hyperpolarization and is thought to regulate neuronal excitability by contributing to the slow component of synaptic AHP. The encoded protein is an integral membrane protein that forms a voltage-independent calcium-activated channel with three other calmodulin-binding subunits. This gene is a member of the KCNN family of potassium channel genes. [provided by RefSeq, Jul 2008]

KCNN1 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.42377925).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
KCNN1	NM_001386974.1	c.484G>A	p.Ala162Thr	missense_variant	3/10	ENST00000684775.1	NP_001373903.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
KCNN1	ENST00000684775.1	c.484G>A	p.Ala162Thr	missense_variant	3/10		NM_001386974.1	ENSP00000507021.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461470 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 727038

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

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

Feb 16, 2023

The c.484G>A (p.A162T) alteration is located in exon 4 (coding exon 2) of the KCNN1 gene. This alteration results from a G to A substitution at nucleotide position 484, causing the alanine (A) at amino acid position 162 to be replaced by a threonine (T). 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	0.13
BayesDel_addAF	Pathogenic	0.26	D
BayesDel_noAF	Pathogenic	0.14
CADD	Benign	22
DANN	Uncertain	0.98
DEOGEN2	Benign	0.29	T;.
Eigen	Benign	-0.28
Eigen_PC	Benign	-0.18
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Uncertain	0.90	D;D
M_CAP	Benign	0.013	T
MetaRNN	Benign	0.42	T;T
MetaSVM	Benign	-0.96	T
MutationAssessor	Benign	1.8	L;.
PrimateAI	Uncertain	0.61	T
REVEL	Benign	0.16
Sift4G	Benign	0.23	T;T
Polyphen		0.040	B;.
Vest4		0.47
MutPred		0.69		Loss of loop (P = 0.0374);Loss of loop (P = 0.0374);
MVP		0.52
MPC		0.55
ClinPred		0.84	D
GERP RS		3.9
Varity_R		0.32
gMVP		0.85

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: rs1423436676; hg19: chr19-18085982;