rs766602837

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2PP3_Moderate

The NM_024649.5(BBS1):​c.157A>G​(p.Lys53Glu) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.00000248 in 1,613,952 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 2/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. K53K) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

BBS1
NM_024649.5 missense, splice_region

Scores

8
9
2
Splicing: ADA: 0.8909
1
1

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 6.31

Publications

2 publications found
Variant links:
Genes affected
BBS1 (HGNC:966): (Bardet-Biedl syndrome 1) Mutations in this gene have been observed in patients with the major form (type 1) of Bardet-Biedl syndrome. The encoded protein may play a role in eye, limb, cardiac and reproductive system development. [provided by RefSeq, Jul 2008]
BBS1 Gene-Disease associations (from GenCC):
  • Bardet-Biedl syndrome 1
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, G2P, Myriad Women’s Health, Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
  • ciliopathy
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • Bardet-Biedl syndrome
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.84

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
BBS1NM_024649.5 linkc.157A>G p.Lys53Glu missense_variant, splice_region_variant Exon 3 of 17 ENST00000318312.12 NP_078925.3

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
BBS1ENST00000318312.12 linkc.157A>G p.Lys53Glu missense_variant, splice_region_variant Exon 3 of 17 1 NM_024649.5 ENSP00000317469.7
ENSG00000256349ENST00000419755.3 linkc.268A>G p.Lys90Glu missense_variant, splice_region_variant Exon 3 of 17 2 ENSP00000398526.3

Frequencies

GnomAD3 genomes
AF:
0.00000658
AC:
1
AN:
152064
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.000193
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
GnomAD2 exomes
AF:
0.0000119
AC:
3
AN:
251452
AF XY:
0.00000736
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.000163
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000205
AC:
3
AN:
1461888
Hom.:
0
Cov.:
33
AF XY:
0.00000275
AC XY:
2
AN XY:
727246
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.0000252
AC:
1
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1112006
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
1
2
2
3
4
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:
0.00000658
AC:
1
AN:
152064
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74272
show subpopulations
⚠️ 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:
41398
American (AMR)
AF:
0.00
AC:
0
AN:
15250
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.000193
AC:
1
AN:
5182
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10602
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68014
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.325
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:
0.0000378
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Bardet-Biedl syndrome 1 Uncertain:2
Nov 30, 2020
Natera, Inc.
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Aug 19, 2021
Fulgent Genetics, Fulgent Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Bardet-Biedl syndrome Uncertain:1
May 29, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces lysine, which is basic and polar, with glutamic acid, which is acidic and polar, at codon 53 of the BBS1 protein (p.Lys53Glu). 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 missense change has been observed in individual(s) with Bardet-Biedl syndrome (PMID: 12677556). ClinVar contains an entry for this variant (Variation ID: 462953). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). Experimental studies have shown that this missense change affects BBS1 function (PMID: 20498079). 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
Uncertain
0.51
BayesDel_addAF
Pathogenic
0.26
D
BayesDel_noAF
Pathogenic
0.40
CADD
Pathogenic
30
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.93
.;D;D;.;D;.
Eigen
Pathogenic
0.79
Eigen_PC
Pathogenic
0.76
FATHMM_MKL
Uncertain
0.96
D
LIST_S2
Benign
0.75
T;T;T;T;T;T
M_CAP
Uncertain
0.22
D
MetaRNN
Pathogenic
0.84
D;D;D;D;D;D
MetaSVM
Pathogenic
0.89
D
MutationAssessor
Uncertain
2.9
.;M;.;.;.;M
PhyloP100
6.3
PrimateAI
Uncertain
0.66
T
PROVEAN
Uncertain
-2.9
D;D;D;N;D;D
REVEL
Pathogenic
0.88
Sift
Uncertain
0.013
D;D;D;T;T;D
Sift4G
Uncertain
0.033
D;D;D;D;D;D
Polyphen
0.99, 1.0
.;D;.;.;D;.
Vest4
0.89
MutPred
0.79
.;Loss of ubiquitination at K53 (P = 0.011);.;Loss of ubiquitination at K53 (P = 0.011);Loss of ubiquitination at K53 (P = 0.011);Loss of ubiquitination at K53 (P = 0.011);
MVP
0.97
MPC
0.77
ClinPred
0.82
D
GERP RS
5.7
PromoterAI
0.033
Neutral
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.63
gMVP
0.79
Mutation Taster
=2/98
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.89
dbscSNV1_RF
Pathogenic
0.89
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: rs766602837; hg19: chr11-66278708; API