dbSNP rs75295839: BBS4:p.Lys46Thr (chr15-72709760-A-C) – ACMG Classification: Uncertain_significance (2 pts)

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_033028.5(BBS4):c.137A>C(p.Lys46Thr) variant causes a missense change. The variant allele was found at a frequency of 0.00000186 in 1,613,434 control chromosomes in the GnomAD database, with no homozygous occurrence. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. K46R) has been classified as Benign.

Frequency

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

Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

BBS4
NM_033028.5 missense

Scores

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 6.34

Publications

12 publications found

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]

BBS4 Gene-Disease associations (from GenCC):

Bardet-Biedl syndrome 4
Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, G2P
ciliopathy
Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
Bardet-Biedl syndrome
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

BBS4 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
BBS4	NM_033028.5 link	c.137A>C	p.Lys46Thr	missense_variant	Exon 3 of 16	ENST00000268057.9	NP_149017.2	Q96RK4-1A0A0S2Z3A9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
BBS4	ENST00000268057.9 link	c.137A>C	p.Lys46Thr	missense_variant	Exon 3 of 16	1	NM_033028.5	ENSP00000268057.4		Q96RK4-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152154

Hom.:

Cov.:

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:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

0.00000137

AC:

AN:

1461280

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

726996

show subpopulations

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR)

AF:

0.00

AC:

AN:

33466

American (AMR)

AF:

0.00

AC:

AN:

44722

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26130

East Asian (EAS)

AF:

0.00

AC:

AN:

39680

South Asian (SAS)

AF:

0.00

AC:

AN:

86252

European-Finnish (FIN)

AF:

0.0000188

AC:

AN:

53254

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5766

European-Non Finnish (NFE)

AF:

9.00e-7

AC:

AN:

1111630

Other (OTH)

AF:

0.00

AC:

AN:

60380

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000203), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.375

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152154

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74330

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41410

American (AMR)

AF:

0.00

AC:

AN:

15276

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5198

South Asian (SAS)

AF:

0.00

AC:

AN:

4832

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10614

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68032

Other (OTH)

AF:

0.00

AC:

AN:

2094

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.725

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<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:

0.00000413

Hom.:

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.80

BayesDel_addAF

Pathogenic

0.17

BayesDel_noAF

Uncertain

0.010

CADD

Uncertain

(source)

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.72

D;.;T

Eigen

Uncertain

0.49

Eigen_PC

Uncertain

0.51

FATHMM_MKL

Uncertain

0.96

LIST_S2

Uncertain

0.95

D;D;D

M_CAP

Benign

0.044

MetaRNN

Uncertain

0.53

D;D;D

MetaSVM

Benign

-0.43

MutationAssessor

Uncertain

2.5

M;.;.

PhyloP100

6.3

PrimateAI

Uncertain

0.64

PROVEAN

Uncertain

-3.9

D;D;D

REVEL

Uncertain

0.31

Sift

Uncertain

0.028

D;D;D

Sift4G

Uncertain

0.028

D;T;D

Polyphen

0.61

P;.;.

Vest4

0.61

MutPred

0.37

Loss of ubiquitination at K46 (P = 0.0134);.;.;

MVP

0.87

MPC

0.050

ClinPred

0.98

GERP RS

5.0

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.74

gMVP

0.62

Mutation Taster

=40/60

disease causing

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.010

Details are displayed if max score is > 0.2

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

Publications

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over