1-160135980-T-G

Variant names:

• chr1-160135980-T-G
• rs1553245805
• NM_000702.4:c.2426T>G

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PM1 PM2 PP2 PP3_Strong

The NM_000702.4(ATP1A2):​c.2426T>G​(p.Leu809Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. L809L) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: ATP1A2 NM_000702.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 8.02
• Publications: 2 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: Likely_pathogenic. The variant received 9 ACMG points.

• PM1: In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 9 uncertain in NM_000702.4
• 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.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.968

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ATP1A2	NM_000702.4	c.2426T>G	p.Leu809Arg	missense_variant	Exon 17 of 23	ENST00000361216.8	NP_000693.1
ATP1A2	XM_047421286.1	c.1535T>G	p.Leu512Arg	missense_variant	Exon 10 of 16		XP_047277242.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ATP1A2	ENST00000361216.8	c.2426T>G	p.Leu809Arg	missense_variant	Exon 17 of 23	1	NM_000702.4	ENSP00000354490.3
ATP1A2	ENST00000392233.7	c.2426T>G	p.Leu809Arg	missense_variant	Exon 17 of 23	5		ENSP00000376066.3
ATP1A2	ENST00000447527.1	c.1556T>G	p.Leu519Arg	missense_variant	Exon 10 of 16	2		ENSP00000411705.1
ATP1A2	ENST00000472488.5	n.2529T>G		non_coding_transcript_exon_variant	Exon 17 of 20	2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Familial hemiplegic migraine Uncertain:1

Aug 17, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces leucine with arginine at codon 809 of the ATP1A2 protein (p.Leu809Arg). The leucine residue is highly conserved and there is a moderate physicochemical difference between leucine and arginine. 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. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with ATP1A2-related disease. This variant is not present in population databases (ExAC no frequency). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.56	D
BayesDel_noAF	Pathogenic	0.57
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.98	D;.
Eigen	Uncertain	0.64
Eigen_PC	Uncertain	0.58
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.99	D;D
M_CAP	Pathogenic	0.65	D
MetaRNN	Pathogenic	0.97	D;D
MetaSVM	Uncertain	0.54	D
MutationAssessor	Pathogenic	4.2	H;.
PhyloP100		8.0
PrimateAI	Pathogenic	0.92	D
PROVEAN	Uncertain	-4.4	D;D
REVEL	Pathogenic	0.97
Sift	Uncertain	0.011	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		0.74	P;.
Vest4		0.97
MutPred		0.84		Gain of methylation at L809 (P = 0.0271);Gain of methylation at L809 (P = 0.0271);
MVP		0.99
MPC		2.6
ClinPred		1.0	D
GERP RS		4.6
Varity_R		0.96
gMVP		1.0
Mutation Taster		=9/91	disease causing

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: rs1553245805; hg19: chr1-160105770;