1-231336499-G-T

Variant names:

• chr1-231336499-G-T
• rs369247477
• NM_175876.5:c.1247C>A

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PVS1_Strong PM2

The NM_175876.5(EXOC8):​c.1247C>A​(p.Ser416*) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,456 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: EXOC8 NM_175876.5 stop_gained
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 8.00
• Publications: 0 publications found

Genes affected

EXOC8 (HGNC:24659): (exocyst complex component 8) This gene encodes a component of the exocyst complex, an evolutionarily conserved multi-protein complex that plays a critical role in vesicular trafficking and the secretory pathway by targeting post-Golgi vesicles to the plasma membrane. This protein is a target of activated Ral subfamily of GTPases and thereby regulates exocytosis by tethering vesicles to the plasma membrane. Mutations in this gene may be related to Joubert syndrome. [provided by RefSeq, Sep 2016]

EXOC8 Gene-Disease associations (from GenCC):

• neurodevelopmental disorder with microcephaly, seizures, and brain atrophy

  Inheritance: AR Classification: STRONG, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.427 CDS is truncated, and there are 1 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_175876.5. 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
	EXOC8	NM_175876.5	MANE Select	c.1247C>A	p.Ser416*	stop_gained	Exon 1 of 1	NP_787072.2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	EXOC8	ENST00000366645.1	TSL:6 MANE Select	c.1247C>A	p.Ser416*	stop_gained	Exon 1 of 1	ENSP00000355605.2	Q8IYI6

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461456 Hom.: 0 Cov.: 32 AF XY: 0.00000275 AC XY: 2 AN XY: 726956

African (AFR) AF: 0.00 AC: 0 AN: 33472

American (AMR) AF: 0.00 AC: 0 AN: 44698

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26114

East Asian (EAS) AF: 0.00 AC: 0 AN: 39694

South Asian (SAS) AF: 0.00 AC: 0 AN: 86208

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53312

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1111812

Other (OTH) AF: 0.0000166 AC: 1 AN: 60378

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Pathogenic	0.58
CADD	Pathogenic	38
DANN	Uncertain	0.99
Eigen	Pathogenic	0.99
Eigen_PC	Pathogenic	0.88
FATHMM_MKL	Uncertain	0.95	D
PhyloP100		8.0
Vest4		0.43
GERP RS		5.9
Mutation Taster		=6/194	disease causing

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

dbSNP: rs369247477; hg19: chr1-231472245;