16-56192574-G-T

Position:

• chr16-56192574-G-T

Variant summary

Our verdict is Pathogenic. Variant got 13 ACMG points: 13P and 0B. PM1 PM2 PM5 PP2 PP3_Strong PP5_Moderate

The ENST00000262493.12(GNAO1):​c.119G>T​(p.Gly40Val) variant causes a missense, splice region 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. 14/23 in silico tools predict a damaging outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G40A) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 26)
• Consequence: GNAO1 ENST00000262493.12 missense, splice_region
• Scores: Splicing: ADA: 0.9996
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 9.60

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-AS1 (HGNC:24498): (GNAO1 antisense RNA 1)

ACMG classification

Verdict is Pathogenic. Variant got 13 ACMG points.

• PM1: In a hotspot region, there are 6 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 uncertain in ENST00000262493.12
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr16-56192574-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 280589.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), GNAO1. . Gene score misZ 3.1919 (greater than the threshold 3.09). Trascript score misZ 4.549 (greater than threshold 3.09). GenCC has associacion of gene with developmental and epileptic encephalopathy, 17, neurodevelopmental disorder with involuntary movements, developmental and epileptic encephalopathy, movement disorder.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.993
• PP5: Variant 16-56192574-G-T is Pathogenic according to our data. Variant chr16-56192574-G-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 587482.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
GNAO1	NM_020988.3	c.119G>T	p.Gly40Val	missense_variant, splice_region_variant	2/9	ENST00000262493.12	NP_066268.1
GNAO1-AS1	NR_026889.1			downstream_gene_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
GNAO1	ENST00000262493.12	c.119G>T	p.Gly40Val	missense_variant, splice_region_variant	2/9	1	NM_020988.3	ENSP00000262493	P1
GNAO1-AS1	ENST00000567381.1			downstream_gene_variant

Frequencies

GnomAD3 genomes Cov.: 26

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 26

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

Developmental and epileptic encephalopathy, 1 Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Genomic Research Center, Shahid Beheshti University of Medical Sciences

Aug 07, 2018

- -

Neurodevelopmental disorder with involuntary movements Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Genomic Research Center, Shahid Beheshti University of Medical Sciences

Aug 07, 2018

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.60
CADD	Pathogenic	32
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.96	D;.;D;.;D;.
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.93
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Pathogenic	0.99	.;D;D;D;D;D
M_CAP	Pathogenic	0.97	D
MetaRNN	Pathogenic	0.99	D;D;D;D;D;D
MetaSVM	Pathogenic	0.97	D
MutationAssessor	Pathogenic	4.5	H;.;H;H;.;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Pathogenic	0.90	D
PROVEAN	Pathogenic	-7.1	D;.;.;D;.;.
REVEL	Pathogenic	0.99
Sift	Pathogenic	0.0	D;.;.;D;.;.
Sift4G	Pathogenic	0.0	D;.;.;D;D;.
Polyphen		1.0	D;.;D;D;.;.
Vest4		0.95
MutPred		0.95		Loss of sheet (P = 0.0457);Loss of sheet (P = 0.0457);Loss of sheet (P = 0.0457);Loss of sheet (P = 0.0457);Loss of sheet (P = 0.0457);Loss of sheet (P = 0.0457);
MVP		0.98
MPC		2.4
ClinPred		1.0	D
GERP RS		4.7
Varity_R		0.98
gMVP		1.0

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.98
SpliceAI score (max)		0.020		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: rs886041766; hg19: chr16-56226486;