3-94003907-G-T

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2PP3

The NM_001174150.2(ARL13B):​c.379G>T​(p.Val127Leu) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000248 in 1,613,274 control chromosomes in the GnomAD database, with no homozygous occurrence. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000023 ( 0 hom. )

Consequence

ARL13B
NM_001174150.2 missense, splice_region

Scores

2
9
8
Splicing: ADA: 0.9911
2

Clinical Significance

Uncertain significance criteria provided, single submitter U:1B:1

Conservation

PhyloP100: 10.0

Publications

1 publications found
Variant links:
Genes affected
ARL13B (HGNC:25419): (ADP ribosylation factor like GTPase 13B) This gene encodes a member of the ADP-ribosylation factor-like family. The encoded protein is a small GTPase that contains both N-terminal and C-terminal guanine nucleotide-binding motifs. This protein is localized in the cilia and plays a role in cilia formation and in maintenance of cilia. Mutations in this gene are the cause of Joubert syndrome 8. Alternate splicing results in multiple transcript variants. [provided by RefSeq, Mar 2010]
ARL13B Gene-Disease associations (from GenCC):
  • Joubert syndrome
    Inheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
  • Joubert syndrome 8
    Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. Scorers claiming Benign: max_spliceai.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
ARL13BNM_001174150.2 linkc.379G>T p.Val127Leu missense_variant, splice_region_variant Exon 3 of 10 ENST00000394222.8 NP_001167621.1 Q3SXY8-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
ARL13BENST00000394222.8 linkc.379G>T p.Val127Leu missense_variant, splice_region_variant Exon 3 of 10 1 NM_001174150.2 ENSP00000377769.3 Q3SXY8-1

Frequencies

GnomAD3 genomes
AF:
0.0000394
AC:
6
AN:
152130
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000241
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:
0.0000588
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000797
AC:
2
AN:
250914
AF XY:
0.00000737
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000289
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000882
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000233
AC:
34
AN:
1461026
Hom.:
0
Cov.:
31
AF XY:
0.0000206
AC XY:
15
AN XY:
726832
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33458
American (AMR)
AF:
0.0000224
AC:
1
AN:
44714
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26114
East Asian (EAS)
AF:
0.0000505
AC:
2
AN:
39608
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86234
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53180
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5762
European-Non Finnish (NFE)
AF:
0.0000252
AC:
28
AN:
1111596
Other (OTH)
AF:
0.0000497
AC:
3
AN:
60360
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.474
Heterozygous variant carriers
0
3
5
8
10
13
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:
0.0000394
AC:
6
AN:
152248
Hom.:
0
Cov.:
32
AF XY:
0.0000537
AC XY:
4
AN XY:
74442
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41568
American (AMR)
AF:
0.0000654
AC:
1
AN:
15288
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5176
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:
294
European-Non Finnish (NFE)
AF:
0.0000588
AC:
4
AN:
67980
Other (OTH)
AF:
0.00
AC:
0
AN:
2110
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.500
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000712
Hom.:
0
Bravo
AF:
0.0000604
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1Benign:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Joubert syndrome 8 Uncertain:1
Jul 31, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces valine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 127 of the ARL13B protein (p.Val127Leu). This variant is present in population databases (rs771933896, gnomAD 0.0009%). This variant has not been reported in the literature in individuals affected with ARL13B-related conditions. ClinVar contains an entry for this variant (Variation ID: 207910). 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: "Tolerated"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). 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. -

Long QT syndrome Benign:1
-
Medical Research Institute, Tokyo Medical and Dental University
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:research

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.48
BayesDel_addAF
Uncertain
0.14
D
BayesDel_noAF
Uncertain
-0.030
CADD
Pathogenic
29
DANN
Uncertain
1.0
DEOGEN2
Benign
0.12
.;T;T
Eigen
Uncertain
0.62
Eigen_PC
Pathogenic
0.68
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Benign
0.54
T;.;D
M_CAP
Benign
0.055
D
MetaRNN
Uncertain
0.70
D;D;D
MetaSVM
Benign
-0.50
T
MutationAssessor
Benign
1.5
.;L;L
PhyloP100
10
PrimateAI
Uncertain
0.59
T
PROVEAN
Benign
-0.94
N;N;N
REVEL
Uncertain
0.35
Sift
Benign
0.28
T;T;T
Sift4G
Uncertain
0.038
D;T;T
Polyphen
0.70
.;P;P
Vest4
0.80
MutPred
0.64
.;Loss of methylation at K131 (P = 0.0754);Loss of methylation at K131 (P = 0.0754);
MVP
0.70
MPC
0.31
ClinPred
0.45
T
GERP RS
5.9
Varity_R
0.28
gMVP
0.80
Mutation Taster
=8/92
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
0.99
dbscSNV1_RF
Pathogenic
0.89
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

Other links and lift over

dbSNP: rs771933896; hg19: chr3-93722751; API