chr15-55319258-G-A

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_004855.5(PIGB):​c.8G>A​(p.Arg3Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000138 in 1,453,710 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. R3R) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

PIGB
NM_004855.5 missense

Scores

1
18

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 1.70

Publications

0 publications found
Variant links:
Genes affected
PIGB (HGNC:8959): (phosphatidylinositol glycan anchor biosynthesis class B) This gene encodes a transmembrane protein that is located in the endoplasmic reticulum and is involved in GPI-anchor biosynthesis. The glycosylphosphatidylinositol (GPI) anchor is a glycolipid found on many blood cells and serves to anchor proteins to the cell surface. This gene is thought to encode a member of a family of dolichol-phosphate-mannose (Dol-P-Man) dependent mannosyltransferases. [provided by RefSeq, Jul 2008]
PIGBOS1 (HGNC:50696): (PIGB opposite strand 1) Involved in regulation of endoplasmic reticulum unfolded protein response. Is integral component of mitochondrial outer membrane. [provided by Alliance of Genome Resources, Apr 2022]
RAB27A (HGNC:9766): (RAB27A, member RAS oncogene family) The protein encoded by this gene belongs to the small GTPase superfamily, Rab family. The protein is membrane-bound and may be involved in protein transport and small GTPase mediated signal transduction. Mutations in this gene are associated with Griscelli syndrome type 2. Alternative splicing occurs at this locus and four transcript variants encoding the same protein have been identified. [provided by RefSeq, Jul 2008]
RAB27A Gene-Disease associations (from GenCC):
  • Griscelli syndrome type 2
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: ClinGen, Labcorp Genetics (formerly Invitae), Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

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 (MetaRNN=0.08511847).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
PIGBNM_004855.5 linkc.8G>A p.Arg3Lys missense_variant Exon 1 of 12 ENST00000164305.10 NP_004846.4 Q92521
PIGBOS1NM_001308421.2 linkc.-470C>T upstream_gene_variant ENST00000436697.3 NP_001295350.1 A0A0B4J2F0

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
PIGBENST00000164305.10 linkc.8G>A p.Arg3Lys missense_variant Exon 1 of 12 1 NM_004855.5 ENSP00000164305.5 Q92521
PIGBENST00000566999.5 linkc.8G>A p.Arg3Lys missense_variant Exon 1 of 6 3 ENSP00000456531.1 H3BS45
PIGBOS1ENST00000436697.3 linkc.-470C>T upstream_gene_variant 2 NM_001308421.2 ENSP00000484893.1 A0A0B4J2F0

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD2 exomes
AF:
0.00
AC:
0
AN:
233380
AF XY:
0.00
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:
0.00000138
AC:
2
AN:
1453710
Hom.:
0
Cov.:
31
AF XY:
0.00
AC XY:
0
AN XY:
722094
show subpopulations
African (AFR)
AF:
0.0000300
AC:
1
AN:
33362
American (AMR)
AF:
0.00
AC:
0
AN:
43564
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25766
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39500
South Asian (SAS)
AF:
0.00
AC:
0
AN:
84064
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52784
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5746
European-Non Finnish (NFE)
AF:
9.02e-7
AC:
1
AN:
1108886
Other (OTH)
AF:
0.00
AC:
0
AN:
60038
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.500
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
Cov.:
32

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

not provided Uncertain:1
Jun 26, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with lysine, which is basic and polar, at codon 3 of the PIGB protein (p.Arg3Lys). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with PIGB-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.093
BayesDel_addAF
Benign
-0.050
T
BayesDel_noAF
Benign
-0.31
CADD
Benign
4.1
DANN
Benign
0.72
DEOGEN2
Benign
0.00094
T;T;T
Eigen
Benign
-0.98
Eigen_PC
Benign
-0.93
FATHMM_MKL
Benign
0.069
N
LIST_S2
Benign
0.37
T;T;T
M_CAP
Benign
0.011
T
MetaRNN
Benign
0.085
T;T;T
MetaSVM
Benign
-1.0
T
MutationAssessor
Benign
1.1
L;.;.
PhyloP100
1.7
PrimateAI
Benign
0.43
T
PROVEAN
Benign
-0.11
N;N;.
REVEL
Benign
0.059
Sift
Pathogenic
0.0
D;D;.
Sift4G
Benign
1.0
T;T;T
Polyphen
0.039
B;.;.
Vest4
0.075
MutPred
0.19
Gain of methylation at R3 (P = 0.0166);Gain of methylation at R3 (P = 0.0166);Gain of methylation at R3 (P = 0.0166);
MVP
0.45
MPC
0.043
ClinPred
0.39
T
GERP RS
2.8
PromoterAI
-0.012
Neutral
Varity_R
0.22
gMVP
0.43
Mutation Taster
=96/4
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

Publications

Other links and lift over

dbSNP: rs772860275; hg19: chr15-55611456; API