1-155277792-C-T

Variant summary

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

The NM_020897.3(HCN3):c.202C>T(p.His68Tyr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000217 in 1,612,380 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: 𝑓 0.000013 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000023 (0 hom.)
• Consequence: HCN3 NM_020897.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.33

Genes affected

HCN3 (HGNC:19183): (hyperpolarization activated cyclic nucleotide gated potassium channel 3) This gene encodes a multi-pass membrane protein that functions as a voltage gated cation channel. The encoded protein is a member of a family of closely related cyclic adenosine monophosphate-binding channel proteins. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Aug 2012]

CLK2 (HGNC:2069): (CDC like kinase 2) This gene encodes a dual specificity protein kinase that phosphorylates serine/threonine and tyrosine-containing substrates. Activity of this protein regulates serine- and arginine-rich (SR) proteins of the spliceosomal complex, thereby influencing alternative transcript splicing. Chromosomal translocations have been characterized between this locus and the PAFAH1B3 (platelet-activating factor acetylhydrolase 1b, catalytic subunit 3 (29kDa)) gene on chromosome 19, resulting in the production of a fusion protein. Note that this gene is distinct from the TELO2 gene (GeneID:9894), which shares the CLK2 alias, but encodes a protein that is involved in telomere length regulation. There is a pseudogene for this gene on chromosome 7. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jun 2014]

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=0.3868379).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
HCN3	NM_020897.3	c.202C>T	p.His68Tyr	missense_variant	1/8	ENST00000368358.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
HCN3	ENST00000368358.4	c.202C>T	p.His68Tyr	missense_variant	1/8	1	NM_020897.3	P1
HCN3	ENST00000496230.5	n.94C>T		non_coding_transcript_exon_variant	1/8	2
CLK2	ENST00000471047.1	n.117+583G>A		intron_variant, non_coding_transcript_variant		3

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152246 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000294

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000162 AC: 4 AN: 247198 Hom.: 0 AF XY: 0.0000149 AC XY: 2 AN XY: 134322

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 SAS exome AF: 0.0000329

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000897

Gnomad OTH exome AF: 0.000333

GnomAD4 exome AF: 0.0000226 AC: 33 AN: 1460134 Hom.: 0 Cov.: 32 AF XY: 0.0000248 AC XY: 18 AN XY: 726306

Gnomad4 AFR exome AF: 0.000329

Gnomad4 AMR exome AF: 0.0000224

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000899

Gnomad4 OTH exome AF: 0.0000664

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152246 Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1 AN XY: 74380

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000294

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000434 Hom.: 0

Bravo AF: 0.0000453

Asia WGS AF: 0.000289 AC: 1 AN: 3478

EpiCase AF: 0.0000545

EpiControl AF: 0.00

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

Nov 12, 2021

The c.202C>T (p.H68Y) alteration is located in exon 1 (coding exon 1) of the HCN3 gene. This alteration results from a C to T substitution at nucleotide position 202, causing the histidine (H) at amino acid position 68 to be replaced by a tyrosine (Y). 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	0.25
BayesDel_addAF	Benign	-0.035	T
BayesDel_noAF	Benign	-0.29
Cadd	Uncertain	25
Dann	Uncertain	1.0
DEOGEN2	Benign	0.25	T
Eigen	Uncertain	0.29
Eigen_PC	Uncertain	0.39
FATHMM_MKL	Benign	0.59	D
M_CAP	Uncertain	0.092	D
MetaRNN	Benign	0.39	T
MetaSVM	Benign	-0.53	T
MutationAssessor	Benign	1.7	L
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.62	T
PROVEAN	Benign	-1.7	N
REVEL	Benign	0.26
Sift	Uncertain	0.0040	D
Sift4G	Uncertain	0.0050	D
Polyphen		0.73	P
Vest4		0.33
MutPred		0.42		Loss of disorder (P = 0.0466);
MVP		0.88
MPC		1.1
ClinPred		0.71	D
GERP RS		5.5
Varity_R		0.32
gMVP		0.56

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: rs931272117; hg19: chr1-155247583;