16-56192291-T-A

Variant names:

• chr16-56192291-T-A
• NM_020988.3:c.56T>A

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM2 PM5 PP3_Strong

The NM_020988.3(GNAO1):​c.56T>A​(p.Ile19Asn) 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. 13/22 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. I19M) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 31)
• Consequence: GNAO1 NM_020988.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.65
• 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-DT (HGNC:27543): (GNAO1 divergent transcript)

ACMG classification

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr16-56192292-T-G is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 2500270.Status of the report is criteria_provided_single_submitter, 1 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.95

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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GNAO1	NM_020988.3	MANE Select	c.56T>A	p.Ile19Asn	missense	Exon 1 of 9	NP_066268.1	P09471-1
	GNAO1	NM_138736.3		c.56T>A	p.Ile19Asn	missense	Exon 1 of 8	NP_620073.2	P09471-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GNAO1	ENST00000262493.12	TSL:1 MANE Select	c.56T>A	p.Ile19Asn	missense	Exon 1 of 9	ENSP00000262493.6	P09471-1
	GNAO1	ENST00000262494.13	TSL:1	c.56T>A	p.Ile19Asn	missense	Exon 1 of 8	ENSP00000262494.7	P09471-2
	GNAO1	ENST00000638705.1	TSL:1	c.56T>A	p.Ile19Asn	missense	Exon 1 of 8	ENSP00000491223.1	P09471-1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 31

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	Developmental and epileptic encephalopathy (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.32	D
BayesDel_noAF	Pathogenic	0.22
CADD	Pathogenic	29
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.93	D
Eigen	Pathogenic	0.83
Eigen_PC	Pathogenic	0.73
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.98	D
M_CAP	Pathogenic	0.88	D
MetaRNN	Pathogenic	0.95	D
MetaSVM	Pathogenic	0.96	D
MutationAssessor	Pathogenic	4.4	H
PhyloP100		7.7
PrimateAI	Pathogenic	0.88	D
PROVEAN	Pathogenic	-4.7	D
REVEL	Pathogenic	0.95
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		0.97	D
Vest4		0.82
MutPred		0.80		Gain of ubiquitination at K21 (P = 0.0545)
MVP		0.90
MPC		3.5
ClinPred		1.0	D
GERP RS		4.8
PromoterAI		-0.12	Neutral
Varity_R		0.98
gMVP		1.0

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

hg19: chr16-56226203;