chr15-55319267-G-T

Variant summary

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

The NM_004855.5(PIGB):​c.17G>T​(p.Ser6Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000187 in 1,607,216 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

PIGB
NM_004855.5 missense

Scores

1
1
17

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 0.545

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: 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=0.103709996).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
PIGBNM_004855.5 linkc.17G>T p.Ser6Ile missense_variant Exon 1 of 12 ENST00000164305.10 NP_004846.4 Q92521
PIGBOS1NM_001308421.2 linkc.-479C>A 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.17G>T p.Ser6Ile missense_variant Exon 1 of 12 1 NM_004855.5 ENSP00000164305.5 Q92521
PIGBENST00000566999.5 linkc.17G>T p.Ser6Ile missense_variant Exon 1 of 6 3 ENSP00000456531.1 H3BS45
PIGBOS1ENST00000436697.3 linkc.-479C>A upstream_gene_variant 2 NM_001308421.2 ENSP00000484893.1 A0A0B4J2F0

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152242
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000241
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.00000137
AC:
2
AN:
1454974
Hom.:
0
Cov.:
31
AF XY:
0.00000277
AC XY:
2
AN XY:
722832
show subpopulations
African (AFR)
AF:
0.0000300
AC:
1
AN:
33388
American (AMR)
AF:
0.0000228
AC:
1
AN:
43786
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25798
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39572
South Asian (SAS)
AF:
0.00
AC:
0
AN:
84318
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52860
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5752
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1109398
Other (OTH)
AF:
0.00
AC:
0
AN:
60102
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.375
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
AF:
0.00000657
AC:
1
AN:
152242
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74380
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41454
American (AMR)
AF:
0.00
AC:
0
AN:
15284
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5200
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4838
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10626
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68048
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.625
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

Genome 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
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.0000113

ClinVar

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

Submissions by phenotype

not provided Uncertain:1
Apr 09, 2023
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. An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant  is likely to be tolerated. This variant has not been reported in the literature in individuals affected with PIGB-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces serine, which is neutral and polar, with isoleucine, which is neutral and non-polar, at codon 6 of the PIGB protein (p.Ser6Ile). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.13
BayesDel_addAF
Benign
-0.047
T
BayesDel_noAF
Benign
-0.30
CADD
Benign
8.2
DANN
Benign
0.93
DEOGEN2
Benign
0.0020
T;T;T
Eigen
Benign
-0.93
Eigen_PC
Benign
-0.97
FATHMM_MKL
Benign
0.056
N
LIST_S2
Benign
0.47
T;T;T
M_CAP
Benign
0.0072
T
MetaRNN
Benign
0.10
T;T;T
MetaSVM
Benign
-1.0
T
MutationAssessor
Benign
1.4
L;.;.
PhyloP100
0.55
PrimateAI
Uncertain
0.48
T
PROVEAN
Benign
-0.40
N;N;.
REVEL
Benign
0.044
Sift
Pathogenic
0.0
D;D;.
Sift4G
Benign
0.53
T;T;T
Polyphen
0.27
B;.;.
Vest4
0.22
MutPred
0.28
Gain of catalytic residue at S6 (P = 0.0213);Gain of catalytic residue at S6 (P = 0.0213);Gain of catalytic residue at S6 (P = 0.0213);
MVP
0.51
MPC
0.050
ClinPred
0.53
D
GERP RS
0.83
PromoterAI
-0.0064
Neutral
Varity_R
0.11
gMVP
0.33

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: rs1053532065; hg19: chr15-55611465; API