NM_024649.5:c.1439C>A

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BP4_Strong

The NM_024649.5(BBS1):​c.1439C>A​(p.Thr480Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000747 in 1,605,562 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign 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. T480M) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000076 ( 0 hom. )

Consequence

BBS1
NM_024649.5 missense

Scores

2
17

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:5

Conservation

PhyloP100: 0.481

Publications

0 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]
ZDHHC24 (HGNC:27387): (zinc finger DHHC-type containing 24) Predicted to enable protein-cysteine S-palmitoyltransferase activity. Predicted to be involved in peptidyl-L-cysteine S-palmitoylation and protein targeting to membrane. Predicted to be integral component of membrane. Predicted to be active in Golgi apparatus and endoplasmic reticulum. [provided by Alliance of Genome Resources, Apr 2022]

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -4 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.041381985).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
BBS1NM_024649.5 linkc.1439C>A p.Thr480Lys missense_variant Exon 14 of 17 ENST00000318312.12 NP_078925.3 Q8NFJ9-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
BBS1ENST00000318312.12 linkc.1439C>A p.Thr480Lys missense_variant Exon 14 of 17 1 NM_024649.5 ENSP00000317469.7 Q8NFJ9-1
ENSG00000256349ENST00000419755.3 linkc.1550C>A p.Thr517Lys missense_variant Exon 14 of 17 2 ENSP00000398526.3

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152176
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000655
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
GnomAD2 exomes
AF:
0.0000331
AC:
8
AN:
241438
AF XY:
0.0000152
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000233
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000757
AC:
11
AN:
1453386
Hom.:
0
Cov.:
34
AF XY:
0.00000415
AC XY:
3
AN XY:
723300
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33460
American (AMR)
AF:
0.000224
AC:
10
AN:
44636
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26100
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39658
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86134
European-Finnish (FIN)
AF:
0.0000219
AC:
1
AN:
45592
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5762
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111732
Other (OTH)
AF:
0.00
AC:
0
AN:
60312
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.480
Heterozygous variant carriers
0
1
2
4
5
6
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:
152176
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74322
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41432
American (AMR)
AF:
0.0000655
AC:
1
AN:
15278
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5192
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10618
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68032
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.575
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000344
Hom.:
0
Bravo
AF:
0.0000227
ExAC
AF:
0.0000330
AC:
4

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:5
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Bardet-Biedl syndrome 1 Uncertain:2
Oct 28, 2019
Natera, Inc.
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Nov 15, 2021
Fulgent Genetics, Fulgent Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Inborn genetic diseases Uncertain:1
Apr 25, 2022
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.1439C>A (p.T480K) alteration is located in exon 14 (coding exon 14) of the BBS1 gene. This alteration results from a C to A substitution at nucleotide position 1439, causing the threonine (T) at amino acid position 480 to be replaced by a lysine (K). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

BBS1-related disorder Uncertain:1
Jun 18, 2024
PreventionGenetics, part of Exact Sciences
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

The BBS1 c.1439C>A variant is predicted to result in the amino acid substitution p.Thr480Lys. To our knowledge, this variant has not been reported in the literature. This variant is reported in 0.026% of alleles in individuals of Latino descent in gnomAD. At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Bardet-Biedl syndrome Uncertain:1
Aug 27, 2021
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces threonine with lysine at codon 480 of the BBS1 protein (p.Thr480Lys). The threonine residue is weakly conserved and there is a moderate physicochemical difference between threonine and lysine. This variant is present in population databases (rs374706769, ExAC 0.04%). This variant has not been reported in the literature in individuals affected with BBS1-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. 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
Benign
0.16
BayesDel_addAF
Benign
-0.25
T
BayesDel_noAF
Benign
-0.31
CADD
Benign
0.88
DANN
Benign
0.72
DEOGEN2
Benign
0.26
.;T;T;.
Eigen
Benign
-1.2
Eigen_PC
Benign
-1.2
FATHMM_MKL
Benign
0.17
N
LIST_S2
Benign
0.42
T;T;T;T
M_CAP
Uncertain
0.11
D
MetaRNN
Benign
0.041
T;T;T;T
MetaSVM
Uncertain
-0.21
T
MutationAssessor
Benign
0.69
.;N;.;.
PhyloP100
0.48
PrimateAI
Benign
0.33
T
PROVEAN
Benign
-1.2
N;N;N;N
REVEL
Benign
0.23
Sift
Benign
0.36
T;T;T;D
Sift4G
Benign
0.81
T;T;T;T
Polyphen
0.062, 0.56
.;B;P;.
Vest4
0.15
MutPred
0.31
.;Gain of ubiquitination at T480 (P = 0.0131);.;.;
MVP
0.51
MPC
0.21
ClinPred
0.029
T
GERP RS
0.14
Varity_R
0.071
gMVP
0.41
Mutation Taster
=88/12
polymorphism

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: rs374706769; hg19: chr11-66297389; API