rs121918612

Variant names:

• chr1-160127704-G-A
• rs121918612
• NM_000702.4:c.901G>A

Variant summary

Our verdict is Pathogenic. The variant received 19 ACMG points: 19P and 0B. PM1 PM2 PM5 PP2 PP3_Strong PP5_Very_Strong

The NM_000702.4(ATP1A2):​c.901G>A​(p.Gly301Arg) 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. 14/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G301E) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: ATP1A2 NM_000702.4 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:3 O:1
• Conservation: PhyloP100: 9.97
• Publications: 33 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: Pathogenic. The variant received 19 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 4 uncertain in NM_000702.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr1-160127705-G-A is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 2020422.Status of the report is criteria_provided_single_submitter, 1 stars.
• 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, 0.992
• PP5: Variant 1-160127704-G-A is Pathogenic according to our data. Variant chr1-160127704-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 12922.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000702.4. 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
	ATP1A2	NM_000702.4	MANE Select	c.901G>A	p.Gly301Arg	missense	Exon 8 of 23	NP_000693.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ATP1A2	ENST00000361216.8	TSL:1 MANE Select	c.901G>A	p.Gly301Arg	missense	Exon 8 of 23	ENSP00000354490.3
	ATP1A2	ENST00000392233.7	TSL:5	c.901G>A	p.Gly301Arg	missense	Exon 8 of 23	ENSP00000376066.3
	ATP1A2	ENST00000447527.1	TSL:2	c.31G>A	p.Gly11Arg	missense	Exon 1 of 16	ENSP00000411705.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3 Other:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Migraine, familial hemiplegic, 2 Pathogenic:2

Sep 01, 2004

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

Dec 07, 2023

3billion

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The variant is not observed in the gnomAD v2.1.1 dataset. Predicted Consequence/Location: Missense changes are a common disease-causing mechanism. In silico tool predictions suggest damaging effect of the variant on gene or gene product [REVEL: 0.94 (>=0.6, sensitivity 0.68 and specificity 0.92); 3Cnet: 0.91 (>=0.6, sensitivity 0.72 and precision 0.9)]. Same nucleotide change resulting in same amino acid change has been previously reported as pathogenic/likely pathogenic with strong evidence (ClinVar ID: VCV000012922 /PMID: 15459825). The variant has been reported to co-segregate with the disease in at least 7 similarly affected relatives/individuals in at least two unrelated families (PMID: 15459825, 21398422). A different missense change at the same codon (p.Gly301Glu) has been reported to be associated with ATP1A2-related disorder (ClinVar ID: VCV002020422). Therefore, this variant is classified as Pathogenic according to the recommendation of ACMG/AMP guideline.

Familial hemiplegic migraine Pathogenic:1 Other:1

GeneReviews

Significance: not provided

Review Status: no classification provided

Collection Method: literature only

Severe phenotype reported

Oct 24, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

For these reasons, this variant has been classified as Pathogenic. Experimental studies have shown that this missense change affects ATP1A2 function (PMID: 19372756, 21398422). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt ATP1A2 protein function. ClinVar contains an entry for this variant (Variation ID: 12922). This missense change has been observed in individuals with familial hemiplegic migraine (PMID: 15459825, 21398422). It has also been observed to segregate with disease in related individuals. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces glycine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 301 of the ATP1A2 protein (p.Gly301Arg).

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.50	D
BayesDel_noAF	Pathogenic	0.48
CADD	Pathogenic	33
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.96	D
Eigen	Pathogenic	0.74
Eigen_PC	Pathogenic	0.71
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D
M_CAP	Pathogenic	0.66	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Uncertain	0.66	D
MutationAssessor	Pathogenic	3.8	H
PhyloP100		10
PrimateAI	Pathogenic	0.92	D
PROVEAN	Pathogenic	-6.7	D
REVEL	Pathogenic	0.94
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.95
MutPred		0.98		Gain of methylation at G301 (P = 0.0062)
MVP		0.98
MPC		2.0
ClinPred		1.0	D
GERP RS		4.9
PromoterAI		0.019	Neutral
Varity_R		0.98
gMVP		1.0
Mutation Taster		=1/99	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		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: rs121918612; hg19: chr1-160097494;