16-1220475-G-T

Variant names:

• chr16-1220475-G-T
• rs117964326
• NM_021098.3:c.6543G>T

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_021098.3(CACNA1H):​c.6543G>T​(p.Ala2181Ala) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000129 in 1,546,704 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. A2181A) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 7.2e-7 (0 hom.)
• Consequence: CACNA1H NM_021098.3 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -2.99
• Publications: 2 publications found

Genes affected

CACNA1H (HGNC:1395): (calcium voltage-gated channel subunit alpha1 H) This gene encodes a T-type member of the alpha-1 subunit family, a protein in the voltage-dependent calcium channel complex. Calcium channels mediate the influx of calcium ions into the cell upon membrane polarization and consist of a complex of alpha-1, alpha-2/delta, beta, and gamma subunits in a 1:1:1:1 ratio. The alpha-1 subunit has 24 transmembrane segments and forms the pore through which ions pass into the cell. There are multiple isoforms of each of the proteins in the complex, either encoded by different genes or the result of alternative splicing of transcripts. Alternate transcriptional splice variants, encoding different isoforms, have been characterized for the gene described here. Studies suggest certain mutations in this gene lead to childhood absence epilepsy (CAE). [provided by RefSeq, Jul 2008]

CACNA1H Gene-Disease associations (from GenCC):

• hyperaldosteronism, familial, type IV

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• childhood absence epilepsy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• epilepsy, childhood absence, susceptibility to, 6

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

ACMG classification

Our verdict: Likely_benign. The variant received -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.8).
• BP7: Synonymous conserved (PhyloP=-2.99 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_021098.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CACNA1H	NM_021098.3	MANE Select	c.6543G>T	p.Ala2181Ala	synonymous	Exon 35 of 35	NP_066921.2
	CACNA1H	NM_001005407.2		c.6525G>T	p.Ala2175Ala	synonymous	Exon 34 of 34	NP_001005407.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CACNA1H	ENST00000348261.11	TSL:1 MANE Select	c.6543G>T	p.Ala2181Ala	synonymous	Exon 35 of 35	ENSP00000334198.7
	CACNA1H	ENST00000569107.6	TSL:1	c.6558G>T	p.Ala2186Ala	synonymous	Exon 34 of 34	ENSP00000454990.2
	CACNA1H	ENST00000711493.1		c.6528G>T	p.Ala2176Ala	synonymous	Exon 34 of 34	ENSP00000518778.1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152138 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000654

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: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 7.17e-7 AC: 1 AN: 1394566 Hom.: 0 Cov.: 35 AF XY: 0.00000145 AC XY: 1 AN XY: 689980

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.0000328 AC: 1 AN: 30504

American (AMR) AF: 0.00 AC: 0 AN: 30650

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 21248

East Asian (EAS) AF: 0.00 AC: 0 AN: 39140

South Asian (SAS) AF: 0.00 AC: 0 AN: 74248

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 48978

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5404

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1087028

Other (OTH) AF: 0.00 AC: 0 AN: 57366

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152138 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74328

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 41442

American (AMR) AF: 0.0000654 AC: 1 AN: 15282

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3468

East Asian (EAS) AF: 0.00 AC: 0 AN: 5174

South Asian (SAS) AF: 0.00 AC: 0 AN: 4834

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10626

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 67998

Other (OTH) AF: 0.00 AC: 0 AN: 2088

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.00 Hom.: 0

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.80
CADD	Benign	0.064
DANN	Benign	0.71
PhyloP100		-3.0

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.050		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: rs117964326; hg19: chr16-1270475;