Genetic Variant GNAO1:p.Ala18Ala (chr16-56192289-G-A) – ACMG Classification: Benign (-8 pts)

Variant summary

Our verdict is Benign. Variant got -8 ACMG points: 0P and 8B. BP4_ModerateBP6BP7BS2

The NM_020988.3(GNAO1):c.54G>A(p.Ala18Ala) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000267 in 1,611,744 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 31)

Exomes 𝑓: 0.000029 ( 0 hom. )

Consequence

GNAO1
NM_020988.3 synonymous

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:1

Conservation

PhyloP100: 1.80

Variant links:

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -8 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.34).

BP6

Variant 16-56192289-G-A is Benign according to our data. Variant chr16-56192289-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 1091992.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=1}.

BP7

Synonymous conserved (PhyloP=1.8 with no splicing effect.

BS2

High AC in GnomAdExome4 at 42 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GNAO1	NM_020988.3 link	c.54G>A	p.Ala18Ala	synonymous_variant	Exon 1 of 9	ENST00000262493.12	NP_066268.1	P09471-1Q8N6I9B3KP89
GNAO1	NM_138736.3 link	c.54G>A	p.Ala18Ala	synonymous_variant	Exon 1 of 8		NP_620073.2	P09471-2Q8N6I9B3KP89Q6AWC5
GNAO1	XR_007064866.1 link	n.801G>A		non_coding_transcript_exon_variant	Exon 1 of 9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GNAO1	ENST00000262493.12 link	c.54G>A	p.Ala18Ala	synonymous_variant	Exon 1 of 9	1	NM_020988.3	ENSP00000262493.6		P09471-1

Frequencies

GnomAD3 genomes

AF:

0.00000658

AC:

AN:

152068

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000405

AC:

AN:

247042

Hom.:

AF XY:

0.00

AC XY:

AN XY:

134444

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000903

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000288

AC:

AN:

1459676

Hom.:

Cov.:

AF XY:

0.0000358

AC XY:

AN XY:

726146

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000369

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000658

AC:

AN:

152068

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74268

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000468

Hom.:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:1

Jan 09, 2023

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this variant does not alter splicing; Has not been previously published as pathogenic or benign to our knowledge -

Early infantile epileptic encephalopathy with suppression bursts

Benign:1

Oct 16, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.34

CADD

Benign

DANN

Benign

0.91

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over