1-160121203-G-C

Variant names:

• chr1-160121203-G-C
• rs61734527
• NM_000702.4:c.129G>C

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2 PP2

The NM_000702.4(ATP1A2):​c.129G>C​(p.Lys43Asn) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. K43R) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: ATP1A2 NM_000702.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.27
• Publications: 0 publications found

Genes affected

ATP1A2 (HGNC:800): (ATPase Na+/K+ transporting subunit alpha 2) The protein encoded by this gene belongs to the family of P-type cation transport ATPases, and to the subfamily of Na+/K+ -ATPases. Na+/K+ -ATPase is an integral membrane protein responsible for establishing and maintaining the electrochemical gradients of Na and K ions across the plasma membrane. These gradients are essential for osmoregulation, for sodium-coupled transport of a variety of organic and inorganic molecules, and for electrical excitability of nerve and muscle. This enzyme is composed of two subunits, a large catalytic subunit (alpha) and a smaller glycoprotein subunit (beta). The catalytic subunit of Na+/K+ -ATPase is encoded by multiple genes. This gene encodes an alpha 2 subunit. Mutations in this gene result in familial basilar or hemiplegic migraines, and in a rare syndrome known as alternating hemiplegia of childhood. [provided by RefSeq, Oct 2008]

ATP1A2 Gene-Disease associations (from GenCC):

• hemiplegic migraine-developmental and epileptic encephalopathy spectrum

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• migraine, familial hemiplegic, 2

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Ambry Genetics, Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
• alternating hemiplegia of childhood 1

  Inheritance: AD Classification: STRONG, LIMITED Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), Genomics England PanelApp
• developmental and epileptic encephalopathy 98

  Inheritance: AD Classification: STRONG, MODERATE Submitted by: Ambry Genetics, G2P, Labcorp Genetics (formerly Invitae)
• fetal akinesia, respiratory insufficiency, microcephaly, polymicrogyria, and dysmorphic facies

  Inheritance: AR Classification: STRONG, MODERATE Submitted by: G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• alternating hemiplegia of childhood

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• familial or sporadic hemiplegic migraine

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the ATP1A2 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 63 curated pathogenic missense variants (we use a threshold of 10). The gene has 10 curated benign missense variants. Gene score misZ: 4.7713 (above the threshold of 3.09). Trascript score misZ: 6.824 (above the threshold of 3.09). GenCC associations: The gene is linked to developmental and epileptic encephalopathy 98, fetal akinesia, respiratory insufficiency, microcephaly, polymicrogyria, and dysmorphic facies, migraine, familial hemiplegic, 2, alternating hemiplegia of childhood, alternating hemiplegia of childhood 1, familial or sporadic hemiplegic migraine, hemiplegic migraine-developmental and epileptic encephalopathy spectrum.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ATP1A2	NM_000702.4	c.129G>C	p.Lys43Asn	missense_variant	Exon 3 of 23	ENST00000361216.8	NP_000693.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ATP1A2	ENST00000361216.8	c.129G>C	p.Lys43Asn	missense_variant	Exon 3 of 23	1	NM_000702.4	ENSP00000354490.3
ATP1A2	ENST00000392233.7	c.129G>C	p.Lys43Asn	missense_variant	Exon 3 of 23	5		ENSP00000376066.3
ATP1A2	ENST00000472488.5	n.232G>C		non_coding_transcript_exon_variant	Exon 3 of 20	2
ATP1A2	ENST00000478587.1	n.409G>C		non_coding_transcript_exon_variant	Exon 2 of 2	3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Familial hemiplegic migraine Uncertain:1

Aug 16, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces lysine, which is basic and polar, with asparagine, which is neutral and polar, at codon 43 of the ATP1A2 protein (p.Lys43Asn). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with ATP1A2-related conditions. ClinVar contains an entry for this variant (Variation ID: 1484261). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C65"). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.86
BayesDel_addAF	Benign	-0.019	T
BayesDel_noAF	Benign	-0.27
CADD	Benign	23
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.44	T;.
Eigen	Uncertain	0.49
Eigen_PC	Uncertain	0.41
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.90	D;D
M_CAP	Benign	0.069	D
MetaRNN	Uncertain	0.67	D;D
MetaSVM	Uncertain	-0.055	T
MutationAssessor	Pathogenic	3.1	M;.
PhyloP100		1.3
PrimateAI	Uncertain	0.75	T
PROVEAN	Uncertain	-2.5	N;N
REVEL	Uncertain	0.53
Sift	Uncertain	0.027	D;D
Sift4G	Benign	0.11	T;T
Polyphen		0.99	D;.
Vest4		0.56
MutPred		0.52		Loss of ubiquitination at K43 (P = 0.0039);Loss of ubiquitination at K43 (P = 0.0039);
MVP		0.84
MPC		1.0
ClinPred		0.98	D
GERP RS		3.6
Varity_R		0.34
gMVP		0.68
Mutation Taster		=51/49	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: rs61734527; hg19: chr1-160090993;