chr8-99013787-A-G

Variant names:

• chr8-99013787-A-G
• rs550982475
• ENST00000355155.6:n.-2A>G

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_152564.5(VPS13B):​c.-2A>G variant causes a 5 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000316 in 1,613,970 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 Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.000026 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000032 (0 hom.)
• Consequence: VPS13B NM_152564.5 5_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.362
• Publications: 1 publications found

Genes affected

VPS13B (HGNC:2183): (vacuolar protein sorting 13 homolog B) This gene encodes a potential transmembrane protein that may function in vesicle-mediated transport and sorting of proteins within the cell. This protein may play a role in the development and the function of the eye, hematological system, and central nervous system. Mutations in this gene have been associated with Cohen syndrome. Multiple splice variants encoding distinct isoforms have been identified for this gene. [provided by RefSeq, Jul 2008]

VPS13B-DT (HGNC:54375): (VPS13B divergent transcript)

ACMG classification

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.29).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
VPS13B	NM_017890.5	c.-2A>G		5_prime_UTR_variant	Exon 2 of 62	ENST00000358544.7	NP_060360.3
VPS13B	NM_152564.5	c.-2A>G		5_prime_UTR_variant	Exon 2 of 62	ENST00000357162.7	NP_689777.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
VPS13B	ENST00000358544.7	c.-2A>G		5_prime_UTR_variant	Exon 2 of 62	1	NM_017890.5	ENSP00000351346.2
VPS13B	ENST00000357162.7	c.-2A>G		5_prime_UTR_variant	Exon 2 of 62	1	NM_152564.5	ENSP00000349685.2

Frequencies

GnomAD3 genomes AF: 0.0000263 AC: 4 AN: 152140 Hom.: 0 Cov.: 32

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: 0.0000294

Gnomad OTH AF: 0.000959

GnomAD2 exomes AF: 0.0000318 AC: 8 AN: 251490 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000867

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000352

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.0000322 AC: 47 AN: 1461830 Hom.: 0 Cov.: 31 AF XY: 0.0000206 AC XY: 15 AN XY: 727214

African (AFR) AF: 0.0000299 AC: 1 AN: 33478

American (AMR) AF: 0.0000671 AC: 3 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39696

South Asian (SAS) AF: 0.00 AC: 0 AN: 86254

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53416

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

European-Non Finnish (NFE) AF: 0.0000351 AC: 39 AN: 1111966

Other (OTH) AF: 0.0000662 AC: 4 AN: 60394

GnomAD4 genome AF: 0.0000263 AC: 4 AN: 152140 Hom.: 0 Cov.: 32 AF XY: 0.0000404 AC XY: 3 AN XY: 74314

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

African (AFR) AF: 0.00 AC: 0 AN: 41428

American (AMR) AF: 0.00 AC: 0 AN: 15272

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5192

South Asian (SAS) AF: 0.00 AC: 0 AN: 4832

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10608

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000294 AC: 2 AN: 68024

Other (OTH) AF: 0.000959 AC: 2 AN: 2086

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.000173), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.0000823 Hom.: 0

Bravo AF: 0.0000567

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Inborn genetic diseases Uncertain:1

Mar 12, 2019

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.-2A>G variant is located in the 5' untranslated region (5’ UTR) of the VPS13B gene. This variant results from an A to G substitution 2 bases upstream from the first translated codon. This nucleotide position is not well conserved in available vertebrate species. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.29
CADD	Benign	16
DANN	Benign	0.90
PhyloP100		0.36
Mutation Taster		=296/4	polymorphism

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: rs550982475; hg19: chr8-100026015;