chr16-56336824-C-T

Variant names:

• chr16-56336824-C-T
• rs546569747
• NM_020988.3:c.687C>T

Variant summary

Our verdict is Benign. Variant got -15 ACMG points: 0P and 15B. BP4_Moderate BP6_Very_Strong BP7 BS2

The NM_020988.3(GNAO1):​c.687C>T​(p.Ser229Ser) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000144 in 1,613,196 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

• Frequency:
  • Genomes: 𝑓 0.000092 (0 hom., cov: 34)
  • Exomes 𝑓: 0.00015 (2 hom.)
• Consequence: GNAO1 NM_020988.3 synonymous
• Clinical Significance: Benign/Likely benign criteria provided, multiple submitters, no conflicts B:4
• Conservation: PhyloP100: 0.550

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]

ACMG classification

Verdict is Benign. Variant got -15 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.34).
• BP6: Variant 16-56336824-C-T is Benign according to our data. Variant chr16-56336824-C-T is described in ClinVar as [Likely_benign]. Clinvar id is 415876.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BP7: Synonymous conserved (PhyloP=0.55 with no splicing effect.
• BS2: High AC in GnomAd4 at 14 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GNAO1	NM_020988.3	c.687C>T	p.Ser229Ser	synonymous_variant	Exon 6 of 9	ENST00000262493.12	NP_066268.1
GNAO1	NM_138736.3	c.687C>T	p.Ser229Ser	synonymous_variant	Exon 6 of 8		NP_620073.2
GNAO1	XM_011523003.4	c.561C>T	p.Ser187Ser	synonymous_variant	Exon 6 of 9		XP_011521305.1
GNAO1	XR_007064866.1	n.1434C>T		non_coding_transcript_exon_variant	Exon 6 of 9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GNAO1	ENST00000262493.12	c.687C>T	p.Ser229Ser	synonymous_variant	Exon 6 of 9	1	NM_020988.3	ENSP00000262493.6

Frequencies

GnomAD3 genomes AF: 0.0000920 AC: 14 AN: 152254 Hom.: 0 Cov.: 34

Gnomad AFR AF: 0.0000482

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000771

Gnomad SAS AF: 0.000621

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000588

Gnomad OTH AF: 0.000478

GnomAD3 exomes AF: 0.000284 AC: 71 AN: 249724 Hom.: 0 AF XY: 0.000377 AC XY: 51 AN XY: 135218

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000290

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.000436

Gnomad SAS exome AF: 0.00187

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000885

Gnomad OTH exome AF: 0.000655

GnomAD4 exome AF: 0.000150 AC: 219 AN: 1460824 Hom.: 2 Cov.: 31 AF XY: 0.000202 AC XY: 147 AN XY: 726736

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.000227

Gnomad4 SAS exome AF: 0.00181

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000117

Gnomad4 OTH exome AF: 0.000679

GnomAD4 genome AF: 0.0000919 AC: 14 AN: 152372 Hom.: 0 Cov.: 34 AF XY: 0.000107 AC XY: 8 AN XY: 74518

Gnomad4 AFR AF: 0.0000481

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.000772

Gnomad4 SAS AF: 0.000621

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000588

Gnomad4 OTH AF: 0.000473

Alfa AF: 0.000130 Hom.: 0

Bravo AF: 0.0000907

Asia WGS AF: 0.00173 AC: 6 AN: 3478

EpiCase AF: 0.000109

EpiControl AF: 0.00

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Inborn genetic diseases Benign:1

Apr 13, 2017

Ambry Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Early infantile epileptic encephalopathy with suppression bursts Benign:1

Dec 28, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided Benign:1

Feb 13, 2020

GeneDx

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

GNAO1-related disorder Benign:1

May 28, 2019

PreventionGenetics, part of Exact Sciences

Significance: Likely benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.34
CADD	Benign	17
DANN	Benign	0.84

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

Other links and lift over

dbSNP: rs546569747; hg19: chr16-56370736;