rs1419955498

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM2PM5PP3

The NM_033028.5(BBS4):​c.1172C>T​(p.Ala391Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000062 in 1,613,976 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A391G) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000055 ( 0 hom. )

Consequence

BBS4
NM_033028.5 missense

Scores

11
6
2

Clinical Significance

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

Conservation

PhyloP100: 7.56
Variant links:
Genes affected
BBS4 (HGNC:969): (Bardet-Biedl syndrome 4) This gene is a member of the Bardet-Biedl syndrome (BBS) gene family. Bardet-Biedl syndrome is an autosomal recessive disorder characterized by severe pigmentary retinopathy, obesity, polydactyly, renal malformation and cognitive disability. The proteins encoded by BBS gene family members are structurally diverse. The similar phenotypes exhibited by mutations in BBS gene family members are likely due to the protein's shared roles in cilia formation and function. Many BBS proteins localize to the basal bodies, ciliary axonemes, and pericentriolar regions of cells. BBS proteins may also be involved in intracellular trafficking via microtubule-related transport. The protein encoded by this gene has sequence similarity to O-linked N-acetylglucosamine (O-GlcNAc) transferases in plants and archaebacteria and in human forms a multi-protein "BBSome" complex with seven other BBS proteins. Alternate splicing results in multiple transcript variants. [provided by RefSeq, Mar 2016]

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 5 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr15-72735890-C-G is described in Lovd as [Likely_pathogenic].
PP3
MetaRNN computational evidence supports a deleterious effect, 0.829

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
BBS4NM_033028.5 linkuse as main transcriptc.1172C>T p.Ala391Val missense_variant 14/16 ENST00000268057.9 NP_149017.2

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
BBS4ENST00000268057.9 linkuse as main transcriptc.1172C>T p.Ala391Val missense_variant 14/161 NM_033028.5 ENSP00000268057 P1Q96RK4-1

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152120
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000131
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:
0.0000119
AC:
3
AN:
251470
Hom.:
0
AF XY:
0.0000147
AC XY:
2
AN XY:
135906
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000578
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:
0.00000879
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000547
AC:
8
AN:
1461856
Hom.:
0
Cov.:
31
AF XY:
0.00000550
AC XY:
4
AN XY:
727238
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.0000894
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:
0.00000180
Gnomad4 OTH exome
AF:
0.0000331
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152120
Hom.:
0
Cov.:
32
AF XY:
0.0000269
AC XY:
2
AN XY:
74298
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.000131
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:
0.0000434
Hom.:
0
Bravo
AF:
0.0000113

ClinVar

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

Submissions by phenotype

not specified Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingGenetic Services Laboratory, University of ChicagoOct 11, 2016- -
Bardet-Biedl syndrome 4 Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingFulgent Genetics, Fulgent GeneticsMar 16, 2022- -
Bardet-Biedl syndrome Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpNov 06, 2023This sequence change replaces alanine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 391 of the BBS4 protein (p.Ala391Val). This variant is present in population databases (no rsID available, gnomAD 0.006%). This variant has not been reported in the literature in individuals affected with BBS4-related conditions. ClinVar contains an entry for this variant (Variation ID: 434495). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on BBS4 protein function. 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
Pathogenic
0.74
BayesDel_addAF
Pathogenic
0.20
D
BayesDel_noAF
Pathogenic
0.22
CADD
Uncertain
26
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.80
.;D
Eigen
Pathogenic
0.73
Eigen_PC
Pathogenic
0.71
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Uncertain
0.95
D;D
M_CAP
Uncertain
0.14
D
MetaRNN
Pathogenic
0.83
D;D
MetaSVM
Pathogenic
0.86
D
MutationAssessor
Pathogenic
3.3
.;M
MutationTaster
Benign
1.0
D;D;D;D
PrimateAI
Benign
0.41
T
PROVEAN
Uncertain
-3.3
.;D
REVEL
Pathogenic
0.76
Sift
Uncertain
0.017
.;D
Sift4G
Uncertain
0.0060
D;D
Polyphen
0.99
.;D
Vest4
0.79
MutPred
0.58
.;Loss of disorder (P = 0.074);
MVP
0.90
MPC
0.071
ClinPred
0.95
D
GERP RS
5.7
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1
Varity_R
0.43
gMVP
0.57

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.020
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: rs1419955498; hg19: chr15-73028231; COSMIC: COSV51439905; COSMIC: COSV51439905; API