rs1191317490

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2BP4_Strong

The NM_004855.5(PIGB):​c.40G>A​(p.Gly14Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000206 in 1,454,264 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 (★★).

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

PIGB
NM_004855.5 missense

Scores

19

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: -1.71

Publications

1 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: Likely_benign. The variant received -2 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.042689323).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
PIGBNM_004855.5 linkc.40G>A p.Gly14Ser missense_variant Exon 1 of 12 ENST00000164305.10 NP_004846.4 Q92521
PIGBOS1NM_001308421.2 linkc.-502C>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.40G>A p.Gly14Ser missense_variant Exon 1 of 12 1 NM_004855.5 ENSP00000164305.5 Q92521
PIGBENST00000566999.5 linkc.40G>A p.Gly14Ser missense_variant Exon 1 of 6 3 ENSP00000456531.1 H3BS45
PIGBOS1ENST00000436697.3 linkc.-502C>T upstream_gene_variant 2 NM_001308421.2 ENSP00000484893.1 A0A0B4J2F0

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD2 exomes
AF:
0.00000427
AC:
1
AN:
233984
AF XY:
0.00000787
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:
0.00000206
AC:
3
AN:
1454264
Hom.:
0
Cov.:
31
AF XY:
0.00000138
AC XY:
1
AN XY:
722412
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33392
American (AMR)
AF:
0.00
AC:
0
AN:
43664
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25772
East Asian (EAS)
AF:
0.0000253
AC:
1
AN:
39550
South Asian (SAS)
AF:
0.00
AC:
0
AN:
84202
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52798
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5752
European-Non Finnish (NFE)
AF:
0.00000180
AC:
2
AN:
1109050
Other (OTH)
AF:
0.00
AC:
0
AN:
60084
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.442
Heterozygous variant carriers
0
1
1
2
2
3
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:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Inborn genetic diseases Uncertain:1
Aug 02, 2021
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.40G>A (p.G14S) alteration is located in exon 1 (coding exon 1) of the PIGB gene. This alteration results from a G to A substitution at nucleotide position 40, causing the glycine (G) at amino acid position 14 to be replaced by a serine (S). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

not provided Uncertain:1
Mar 24, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The serine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. This variant has not been reported in the literature in individuals affected with PIGB-related conditions. The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This sequence change replaces glycine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 14 of the PIGB protein (p.Gly14Ser). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.091
BayesDel_addAF
Benign
-0.21
T
BayesDel_noAF
Benign
-0.53
CADD
Benign
0.36
DANN
Benign
0.85
DEOGEN2
Benign
0.0038
T;T;T
Eigen
Benign
-1.6
Eigen_PC
Benign
-1.6
FATHMM_MKL
Benign
0.027
N
LIST_S2
Benign
0.44
T;T;T
M_CAP
Benign
0.0043
T
MetaRNN
Benign
0.043
T;T;T
MetaSVM
Benign
-1.0
T
MutationAssessor
Benign
1.8
L;.;.
PhyloP100
-1.7
PrimateAI
Benign
0.30
T
PROVEAN
Benign
0.020
N;N;.
REVEL
Benign
0.029
Sift
Benign
0.50
T;T;.
Sift4G
Benign
0.27
T;T;T
Polyphen
0.0020
B;.;.
Vest4
0.13
MutPred
0.20
Gain of glycosylation at G14 (P = 0.0085);Gain of glycosylation at G14 (P = 0.0085);Gain of glycosylation at G14 (P = 0.0085);
MVP
0.16
MPC
0.043
ClinPred
0.047
T
GERP RS
-0.49
PromoterAI
0.015
Neutral
Varity_R
0.028
gMVP
0.18
Mutation Taster
=99/1
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: rs1191317490; hg19: chr15-55611488; API