chr15-84839087-C-T

Position:

• chr15-84839087-C-T

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_020778.5(ALPK3):​c.412C>T​(p.Gln138Ter) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000481 in 1,455,394 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000048 (0 hom.)
• Consequence: ALPK3 NM_020778.5 stop_gained
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 7.46

Genes affected

ALPK3 (HGNC:17574): (alpha kinase 3) Predicted to enable ATP binding activity; protein serine kinase activity; and protein serine/threonine kinase activity. Predicted to be involved in cardiac muscle cell development. Predicted to be active in nucleus. Implicated in hypertrophic cardiomyopathy. [provided by Alliance of Genome Resources, Apr 2022]

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 15-84839087-C-T is Pathogenic according to our data. Variant chr15-84839087-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 504882.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ALPK3	NM_020778.5	c.412C>T	p.Gln138Ter	stop_gained	4/14	ENST00000258888.6	NP_065829.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ALPK3	ENST00000258888.6	c.412C>T	p.Gln138Ter	stop_gained	4/14	1	NM_020778.5	ENSP00000258888	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000481 AC: 7 AN: 1455394 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 723424

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: 0.00000631

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jun 17, 2023

For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 504882). This premature translational stop signal has been observed in individual(s) with ALPK3-related conditions (PMID: 32480058). This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Gln340*) in the ALPK3 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in ALPK3 are known to be pathogenic (PMID: 21441111, 26846950, 27106955, 34263907). -

Hypertrophic cardiomyopathy Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Oct 28, 2015

The p.Gln340X variant in ALPK3 has not been previously reported in individuals w ith cardiomyopathy and was absent from large population studies. This nonsense v ariant leads to a premature termination codon at position 340, which is predicte d to lead to a truncated or absent protein. Biallelic loss-of-function (LOF) var iants in the ALPK3 gene have been reported in multiple individuals and in a mous e model with cardiomyopathy (HCM or mixed HCM/DCM; Almomani 2016, Phelan 2016, V an Sligtenhorst 2012). In summary, although additional studies are required to f ully establish its clinical significance, the p.Gln340X variant is likely pathog enic. ACMG/AMP Criteria applied: PM2, PVS1_Strong. -

Cardiovascular phenotype Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Jul 07, 2021

The p.Q340* pathogenic mutation (also known as c.1018C>T), located in coding exon 4 of the ALPK3 gene, results from a C to T substitution at nucleotide position 1018. This changes the amino acid from a glutamine to a stop codon within coding exon 4. This variant was detected in a pediatric cardiomyopathy case and reported in trans with a second pathogenic variant in ALPK3 (Herkert JC et al. Am Heart J, 2020 07;225:108-119). In addition to the clinical data presented in the literature, this alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.60	D
BayesDel_noAF	Pathogenic	0.62
CADD	Pathogenic	38
DANN	Uncertain	1.0
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.93
FATHMM_MKL	Uncertain	0.96	D
MutationTaster	Benign	1.0	A
Vest4		0.36
GERP RS		4.9

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: rs200889953; hg19: chr15-85382318;