2-169503178-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The ENST00000295240.8(BBS5):ā€‹c.900G>Cā€‹(p.Val300=) variant causes a splice region, synonymous change. The variant allele was found at a frequency of 0.0000243 in 1,607,098 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (ā˜…ā˜…).

Frequency

Genomes: š‘“ 0.0000066 ( 0 hom., cov: 32)
Exomes š‘“: 0.000026 ( 0 hom. )

Consequence

BBS5
ENST00000295240.8 splice_region, synonymous

Scores

2
Splicing: ADA: 0.9999
2

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4B:1

Conservation

PhyloP100: 3.88
Variant links:
Genes affected
BBS5 (HGNC:970): (Bardet-Biedl syndrome 5) This gene encodes a protein that has been directly linked to Bardet-Biedl syndrome. The primary features of this syndrome include retinal dystrophy, obesity, polydactyly, renal abnormalities and learning disabilities. Experimentation in non-human eukaryotes suggests that this gene is expressed in ciliated cells and that it is required for the formation of cilia. Alternate transcriptional splice variants have been observed but have not been fully characterized. [provided by RefSeq, Jul 2008]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PM2
Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
BBS5NM_152384.3 linkuse as main transcriptc.900G>C p.Val300= splice_region_variant, synonymous_variant 10/12 ENST00000295240.8 NP_689597.1

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
BBS5ENST00000295240.8 linkuse as main transcriptc.900G>C p.Val300= splice_region_variant, synonymous_variant 10/121 NM_152384.3 ENSP00000295240 P1Q8N3I7-1
BBS5ENST00000392663.6 linkuse as main transcriptc.837G>C p.Val279= splice_region_variant, synonymous_variant 9/111 ENSP00000376431 Q8N3I7-2
BBS5ENST00000472667.1 linkuse as main transcriptn.671G>C splice_region_variant, non_coding_transcript_exon_variant 2/42

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152158
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
GnomAD3 exomes
AF:
0.0000239
AC:
6
AN:
250602
Hom.:
0
AF XY:
0.0000369
AC XY:
5
AN XY:
135464
show subpopulations
Gnomad AFR exome
AF:
0.0000618
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000441
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000261
AC:
38
AN:
1454940
Hom.:
0
Cov.:
29
AF XY:
0.0000318
AC XY:
23
AN XY:
724268
show subpopulations
Gnomad4 AFR exome
AF:
0.0000300
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000326
Gnomad4 OTH exome
AF:
0.0000166
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152158
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74330
show subpopulations
Gnomad4 AFR
AF:
0.0000241
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.00
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000282
Hom.:
0
Bravo
AF:
0.00000756
EpiCase
AF:
0.00
EpiControl
AF:
0.0000594

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:4Benign:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingWomen's Health and Genetics/Laboratory Corporation of America, LabCorpFeb 21, 2022Variant summary: BBS5 c.900G>C (p.Val300Val) alters a conserved nucleotide located close to a canonical splice site and therefore could affect mRNA splicing, leading to a significantly altered protein sequence. Several computational tools predict a significant impact on normal splicing: Two predict the variant abolishes a canonical 5 prime splicing donor site. One predict the variant weakens a canonical 5 prime donor site. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 2.4e-05 in 250602 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.900G>C has been reported in the literature in an individual affected with cone dystrophy without strong evidence for causality (Carss_2017). These data do not allow any conclusion about variant significance. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. One clinical diagnostic laboratory has submitted clinical-significance assessments for this variant to ClinVar after 2014 and classified the variant as likely benign. Based on the evidence outlined above, the variant was classified as uncertain significance. -
Retinal dystrophy Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingInstitute of Human Genetics, Univ. Regensburg, Univ. RegensburgJan 01, 2022- -
Bardet-Biedl syndrome Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpJun 27, 2022This sequence change affects codon 300 of the BBS5 mRNA. It is a 'silent' change, meaning that it does not change the encoded amino acid sequence of the BBS5 protein. This variant also falls at the last nucleotide of exon 10, which is part of the consensus splice site for this exon. This variant is present in population databases (rs757001492, gnomAD 0.008%). This variant has been observed in individual(s) with inherited retinal dystrophy (PMID: 28041643). ClinVar contains an entry for this variant (Variation ID: 437994). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. 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. -
Bardet-Biedl syndrome 5 Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingFulgent Genetics, Fulgent GeneticsNov 10, 2021- -
Cone dystrophy Benign:1
Likely benign, no assertion criteria providedresearchNIHR Bioresource Rare Diseases, University of CambridgeJan 01, 2015- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.34
CADD
Benign
21
DANN
Benign
0.88
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
2.8

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.97
SpliceAI score (max)
0.14
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs757001492; hg19: chr2-170359688; API