5-114362672-C-G

Variant names:

• chr5-114362672-C-G
• rs1757466751
• NM_021614.4:c.533C>G

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 1P and 5B. PP2 BP4 BS2

The NM_021614.4(KCNN2):​c.533C>G​(p.Ser178Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000784 in 1,275,542 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 8/11 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S178F) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000078 (0 hom.)
• Consequence: KCNN2 NM_021614.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 1.68
• Publications: 0 publications found

Genes affected

KCNN2 (HGNC:6291): (potassium calcium-activated channel subfamily N member 2) 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. This gene is a member of the KCNN family of potassium channel genes. The encoded protein is an integral membrane protein that forms a voltage-independent calcium-activated channel with three other calmodulin-binding subunits. Alternate splicing of this gene results in multiple transcript variants. [provided by RefSeq, May 2013]

KCNN2 Gene-Disease associations (from GenCC):

• neurodevelopmental disorder with or without variable movement or behavioral abnormalities

  Inheritance: AD Classification: STRONG, MODERATE Submitted by: G2P, Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Likely_benign. The variant received -4 ACMG points.

• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 7 curated pathogenic missense variants (we use a threshold of 10). The gene has 1 curated benign missense variants. Gene score misZ: 2.2857 (below the threshold of 3.09). Trascript score misZ: 1.564 (below the threshold of 3.09). GenCC associations: The gene is linked to neurodevelopmental disorder with or without variable movement or behavioral abnormalities.
• BP4: Computational evidence support a benign effect (MetaRNN=0.2892095).
• BS2: High AC in GnomAdExome4 at 10 AD gene.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_021614.4. 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
	KCNN2	NM_021614.4	MANE Select	c.533C>G	p.Ser178Cys	missense	Exon 1 of 8	NP_067627.3
	KCNN2	NM_001372233.1		c.731C>G	p.Ser244Cys	missense	Exon 6 of 13	NP_001359162.1	A0A3F2YNY5
	KCNN2	NR_174097.1		n.603C>G		non_coding_transcript_exon	Exon 1 of 7

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNN2	ENST00000673685.1	MANE Select	c.533C>G	p.Ser178Cys	missense	Exon 1 of 8	ENSP00000501239.1	A0A669KBH3
	KCNN2	ENST00000512097.10	TSL:5	c.731C>G	p.Ser244Cys	missense	Exon 6 of 13	ENSP00000427120.4	A0A3F2YNY5
	KCNN2	ENST00000631899.2	TSL:5	c.-68C>G		upstream_gene	N/A	ENSP00000487849.2	A0A0J9YW81

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000784 AC: 10 AN: 1275542 Hom.: 0 Cov.: 25 AF XY: 0.00000643 AC XY: 4 AN XY: 621720

African (AFR) AF: 0.00 AC: 0 AN: 27712

American (AMR) AF: 0.00 AC: 0 AN: 20088

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 18684

East Asian (EAS) AF: 0.00 AC: 0 AN: 34262

South Asian (SAS) AF: 0.00 AC: 0 AN: 63386

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 30376

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4886

European-Non Finnish (NFE) AF: 0.00000978 AC: 10 AN: 1022924

Other (OTH) AF: 0.00 AC: 0 AN: 53224

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000756

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_noAF	Benign	-0.41
CADD	Uncertain	25
DANN	Benign	0.92
FATHMM_MKL	Benign	0.63	D
LIST_S2	Benign	0.51	T
MetaRNN	Benign	0.29	T
PhyloP100		1.7
PROVEAN	Uncertain	-3.2	D
Sift	Uncertain	0.0050	D
GERP RS		4.1
PromoterAI		0.0044	Neutral
Mutation Taster		=297/3	polymorphism

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

Other links and lift over

dbSNP: rs1757466751; hg19: chr5-113698369;