rs1555508311

Variant names:

• chr16-56351471-A-G
• rs1555508311
• NM_020988.3:c.811A>G

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PM1 PM2 PM5 PP3_Strong

The NM_020988.3(GNAO1):​c.811A>G​(p.Lys271Glu) 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. 12/20 in silico tools predict a damaging outcome for this variant. 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. K271N) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: GNAO1 NM_020988.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter P:1 U:1
• Conservation: PhyloP100: 9.32
• Publications: 0 publications found

Genes affected

GNAO1 (HGNC:4389): (G protein subunit alpha o1) The protein encoded by this gene represents the alpha subunit of the Go heterotrimeric G-protein signal-transducing complex. Defects in this gene are a cause of early-onset epileptic encephalopathy. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Aug 2015]

GNAO1 Gene-Disease associations (from GenCC):

• developmental and epileptic encephalopathy, 17

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
• genetic developmental and epileptic encephalopathy

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
• movement disorder

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen, Illumina
• neurodevelopmental disorder with involuntary movements

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Pathogenic. The variant received 10 ACMG points.

• PM1: In a hotspot region, there are 6 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 4 uncertain in NM_020988.3
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr16-56351473-G-T is described in ClinVar as Pathogenic. ClinVar VariationId is 1432250.Status of the report is criteria_provided_single_submitter, 1 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.985

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_020988.3. 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
	GNAO1	NM_020988.3	MANE Select	c.811A>G	p.Lys271Glu	missense	Exon 7 of 9	NP_066268.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GNAO1	ENST00000262493.12	TSL:1 MANE Select	c.811A>G	p.Lys271Glu	missense	Exon 7 of 9	ENSP00000262493.6
	GNAO1	ENST00000638705.1	TSL:1	c.811A>G	p.Lys271Glu	missense	Exon 7 of 8	ENSP00000491223.1
	GNAO1	ENST00000640469.2	TSL:5	c.811A>G	p.Lys271Glu	missense	Exon 7 of 9	ENSP00000491875.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 33

ClinVar

ClinVar submissions as Germline

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	Developmental and epileptic encephalopathy (1)
1	-	-	Neurodevelopmental disorder with involuntary movements (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.56	D
BayesDel_noAF	Pathogenic	0.57
CADD	Pathogenic	28
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.95	D
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.98
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Benign	0.84	T
M_CAP	Pathogenic	0.76	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.5	H
PhyloP100		9.3
PROVEAN	Uncertain	-3.7	D
REVEL	Pathogenic	0.98
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.94
MutPred		0.88		Loss of methylation at K271 (P = 0.0112)
MVP		0.99
ClinPred		0.99	D
GERP RS		5.9
Varity_R		0.96

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: rs1555508311; hg19: chr16-56385383;