Genetic Variant GNAO1:p.Asn22Asn (chr16-56192301-C-T) – ACMG Classification: Likely_benign (-3 pts)

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2BP4_ModerateBP6_ModerateBP7

The NM_020988.3(GNAO1):c.66C>T(p.Asn22Asn) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,611,756 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 Likely benign (★).

Frequency

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

Exomes 𝑓: 6.9e-7 ( 0 hom. )

Consequence

GNAO1
NM_020988.3 synonymous

Scores

Clinical Significance

Likely benign criteria provided, single submitter B:1

Conservation

PhyloP100: 3.08

Publications

0 publications found

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:

GNAO1-DT (HGNC:27543): (GNAO1 divergent transcript)

GNAO1-DT links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -3 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.37).

BP6

Variant 16-56192301-C-T is Benign according to our data. Variant chr16-56192301-C-T is described in ClinVar as [Likely_benign]. Clinvar id is 530650.Status of the report is criteria_provided_single_submitter, 1 stars.

BP7

Synonymous conserved (PhyloP=3.08 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GNAO1	NM_020988.3 link	c.66C>T	p.Asn22Asn	synonymous_variant	Exon 1 of 9	ENST00000262493.12	NP_066268.1	P09471-1Q8N6I9B3KP89
GNAO1	NM_138736.3 link	c.66C>T	p.Asn22Asn	synonymous_variant	Exon 1 of 8		NP_620073.2	P09471-2Q8N6I9B3KP89Q6AWC5
GNAO1	XR_007064866.1 link	n.813C>T		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.66C>T	p.Asn22Asn	synonymous_variant	Exon 1 of 9	1	NM_020988.3	ENSP00000262493.6		P09471-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152098

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

GnomAD2 exomes

AF:

0.00000404

AC:

AN:

247604

AF XY:

0.00000742

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 FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

6.85e-7

AC:

AN:

1459658

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

726224

show subpopulations

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR)

AF:

0.00

AC:

AN:

33444

American (AMR)

AF:

0.00

AC:

AN:

44710

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26122

East Asian (EAS)

AF:

0.00

AC:

AN:

39684

South Asian (SAS)

AF:

0.0000116

AC:

AN:

86170

European-Finnish (FIN)

AF:

0.00

AC:

AN:

52578

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1110838

Other (OTH)

AF:

0.00

AC:

AN:

60344

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.325

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152098

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74282

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41412

American (AMR)

AF:

0.00

AC:

AN:

15284

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5158

South Asian (SAS)

AF:

0.00

AC:

AN:

4822

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10606

Middle Eastern (MID)

AF:

0.00

AC:

AN:

314

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68030

Other (OTH)

AF:

0.00

AC:

AN:

2090

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.575

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Developmental and epileptic encephalopathy

Benign:1

Sep 12, 2017

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

-0.37

CADD

Benign

(source)

DANN

Benign

0.92

PhyloP100

3.1

PromoterAI

-0.11

Neutral

(source)

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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

16-56192301-C-T

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over