1-154708031-A-G

Variant summary

Our verdict is Benign. Variant got -7 ACMG points: 1P and 8B. PP2 BP4_Strong BS2

The NM_002249.6(KCNN3):c.2141T>C(p.Ile714Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000194 in 1,613,228 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.00021 (0 hom., cov: 31)
  • Exomes 𝑓: 0.00019 (1 hom.)
• Consequence: KCNN3 NM_002249.6 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.76

Genes affected

KCNN3 (HGNC:6292): (potassium calcium-activated channel subfamily N member 3) 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. This gene belongs to the KCNN family of potassium channels. It encodes an integral membrane protein that forms a voltage-independent calcium-activated channel, which is thought to regulate neuronal excitability by contributing to the slow component of synaptic AHP. This gene contains two CAG repeat regions in the coding sequence. It was thought that expansion of one or both of these repeats could lead to an increased susceptibility to schizophrenia or bipolar disorder, but studies indicate that this is probably not the case. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Feb 2011]

ACMG classification

Verdict is Benign. Variant got -7 ACMG points.

• PP2: Missense variant where missense usually causes diseases, KCNN3
• BP4: Computational evidence support a benign effect (MetaRNN=0.008377314).
• BS2: High AC in GnomAd at 32 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KCNN3	NM_002249.6	c.2141T>C	p.Ile714Thr	missense_variant	8/8	ENST00000271915.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KCNN3	ENST00000271915.9	c.2141T>C	p.Ile714Thr	missense_variant	8/8	1	NM_002249.6	P1

Frequencies

GnomAD3 genomes AF: 0.000210 AC: 32 AN: 152094 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.0000483

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00663

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.0000943

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000882

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.000259 AC: 65 AN: 251014 Hom.: 0 AF XY: 0.000236 AC XY: 32 AN XY: 135632

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000580

Gnomad ASJ exome AF: 0.00498

Gnomad EAS exome AF: 0.0000544

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.0000463

Gnomad NFE exome AF: 0.0000792

Gnomad OTH exome AF: 0.000327

GnomAD4 exome AF: 0.000192 AC: 281 AN: 1461134 Hom.: 1 Cov.: 31 AF XY: 0.000169 AC XY: 123 AN XY: 726720

Gnomad4 AFR exome AF: 0.0000597

Gnomad4 AMR exome AF: 0.0000672

Gnomad4 ASJ exome AF: 0.00605

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000756

Gnomad4 OTH exome AF: 0.000563

GnomAD4 genome AF: 0.000210 AC: 32 AN: 152094 Hom.: 0 Cov.: 31 AF XY: 0.000215 AC XY: 16 AN XY: 74302

Gnomad4 AFR AF: 0.0000483

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00663

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.0000943

Gnomad4 NFE AF: 0.0000882

Gnomad4 OTH AF: 0.00

Alfa AF: 0.000766 Hom.: 0

Bravo AF: 0.000208

TwinsUK AF: 0.000539 AC: 2

ALSPAC AF: 0.00 AC: 0

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000233 AC: 2

ExAC AF: 0.000181 AC: 22

Asia WGS AF: 0.000289 AC: 1 AN: 3478

EpiCase AF: 0.000273

EpiControl AF: 0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Inborn genetic diseases Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jan 26, 2022

The c.2141T>C (p.I714T) alteration is located in exon 8 (coding exon 8) of the KCNN3 gene. This alteration results from a T to C substitution at nucleotide position 2141, causing the isoleucine (I) at amino acid position 714 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	0.10
BayesDel_addAF	Uncertain	0.033	T
BayesDel_noAF	Uncertain	0.0
Cadd	Benign	23
Dann	Uncertain	0.99
DEOGEN2	Benign	0.15	T;T;.;.
Eigen	Benign	-0.40
Eigen_PC	Benign	-0.21
FATHMM_MKL	Benign	0.53	D
LIST_S2	Uncertain	0.87	D;D;D;D
M_CAP	Uncertain	0.099	D
MetaRNN	Benign	0.0084	T;T;T;T
MetaSVM	Uncertain	-0.25	T
MutationTaster	Benign	1.0	N;N;N
PrimateAI	Uncertain	0.54	T
PROVEAN	Benign	0.030	N;.;N;N
REVEL	Uncertain	0.36
Sift	Benign	0.085	T;.;D;D
Sift4G	Benign	0.28	T;T;T;T
Polyphen		0.027	.;.;B;.
Vest4		0.10
MVP		0.70
MPC		1.2
ClinPred		0.062	T
GERP RS		5.1
Varity_R		0.099
gMVP		0.26

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: rs76925601; hg19: chr1-154680507;