rs587783013

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong

The NM_001134831.2(AHI1):​c.2174G>A​(p.Trp725*) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000105 in 1,613,580 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000011 ( 0 hom. )

Consequence

AHI1
NM_001134831.2 stop_gained

Scores

5
1
1

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:10U:1

Conservation

PhyloP100: 7.38

Publications

3 publications found
Variant links:
Genes affected
AHI1 (HGNC:21575): (Abelson helper integration site 1) This gene is apparently required for both cerebellar and cortical development in humans. This gene mutations cause specific forms of Joubert syndrome-related disorders. Joubert syndrome (JS) is a recessively inherited developmental brain disorder with several identified causative chromosomal loci. Alternatively spliced transcript variants encoding different isoforms have been identified. [provided by RefSeq, Oct 2008]
AHI1 Gene-Disease associations (from GenCC):
  • Joubert syndrome 3
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, ClinGen, Laboratory for Molecular Medicine, Ambry Genetics
  • Joubert syndrome
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • Joubert syndrome with ocular defect
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • retinitis pigmentosa
    Inheritance: AR, AD Classification: SUPPORTIVE, LIMITED Submitted by: Ambry Genetics, Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 16 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PP5
Variant 6-135433119-C-T is Pathogenic according to our data. Variant chr6-135433119-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 156382.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
AHI1NM_001134831.2 linkc.2174G>A p.Trp725* stop_gained Exon 16 of 29 ENST00000265602.11 NP_001128303.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
AHI1ENST00000265602.11 linkc.2174G>A p.Trp725* stop_gained Exon 16 of 29 1 NM_001134831.2 ENSP00000265602.6

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152196
Hom.:
0
Cov.:
32
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
GnomAD2 exomes
AF:
0.0000161
AC:
4
AN:
248916
AF XY:
0.00000741
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.000223
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000109
AC:
16
AN:
1461384
Hom.:
0
Cov.:
31
AF XY:
0.00000413
AC XY:
3
AN XY:
726996
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33466
American (AMR)
AF:
0.00
AC:
0
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26124
East Asian (EAS)
AF:
0.000227
AC:
9
AN:
39622
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86250
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53400
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5764
European-Non Finnish (NFE)
AF:
0.00000630
AC:
7
AN:
1111680
Other (OTH)
AF:
0.00
AC:
0
AN:
60358
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.500
Heterozygous variant carriers
0
2
4
5
7
9
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:
152196
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74338
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41464
American (AMR)
AF:
0.00
AC:
0
AN:
15286
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5200
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10606
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68028
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.625
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome 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
Alfa
AF:
0.0000397
Hom.:
0
Bravo
AF:
0.0000227
ExAC
AF:
0.0000248
AC:
3

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:10Uncertain:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:4
-
Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

-
Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

-
Genome Diagnostics Laboratory, University Medical Center Utrecht
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

-
Clinical Genetics, Academic Medical Center
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Joubert syndrome 3 Pathogenic:3Uncertain:1
Sep 18, 2014
Molecular Diagnostics Laboratory, Seoul National University Hospital
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Feb 23, 2015
UW Hindbrain Malformation Research Program, University of Washington
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:research

- -

-
Neurology Department of Pediatrics, The Third Affiliated Hospital of Zhengzhou University
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Oct 17, 2017
Illumina Laboratory Services, Illumina
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The AHI1 c.2174G>A (p.Trp725Ter) stop-gained variant has been reported in at least four studies and is found in a compound heterozygous state in three individuals with Joubert syndrome and in one individual with non-syndromic retinitis pigmentosa (RP) (Seong et al. 2015; Bachmann-Gagescu et al. 2015; Enokizono et al. 2017, Nguyen et al. 2017). All three individuals with Joubert syndrome carried null variants on the second allele and the individual with RP carried a missense variant on the second allele. Authors suggest individuals with one mild and one severe AHI1 variant will have remnant Jouberin activity that is sufficient for ciliary function in all cells except retinal photoreceptor cells (Nguyen et al. 2017). Control data are unavailable for this variant, which is reported at a frequency of 0.000348 in the East Asian population of the Exome Aggregation Consortium. Based on the evidence and the potential impact of stop-gained variants, the p.Trp725Ter variant is classified as likely pathogenic for Joubert syndrome. This variant was observed by ICSL as part of a predisposition screen in an ostensibly healthy population. -

Joubert syndrome Pathogenic:1
Feb 22, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change creates a premature translational stop signal (p.Trp725*) in the AHI1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in AHI1 are known to be pathogenic (PMID: 15322546, 16453322, 28442542, 29186038). This variant is present in population databases (rs587783013, gnomAD 0.02%). This premature translational stop signal has been observed in individual(s) with Joubert syndrome and/or retinitis pigmentosa (PMID: 28431631, 28442542). ClinVar contains an entry for this variant (Variation ID: 156382). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

Leber congenital amaurosis Pathogenic:1
Jul 06, 2020
Institute of Vision Research, Yonsei University College of Medicine
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Retinitis pigmentosa Pathogenic:1
Sep 01, 2016
Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.42
D
BayesDel_noAF
Pathogenic
0.66
CADD
Pathogenic
41
DANN
Uncertain
1.0
Eigen
Pathogenic
0.97
Eigen_PC
Pathogenic
0.85
FATHMM_MKL
Pathogenic
0.99
D
PhyloP100
7.4
Vest4
0.89
ClinPred
1.0
D
GERP RS
5.7
Mutation Taster
=0/200
disease causing (ClinVar)

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: rs587783013; hg19: chr6-135754257; API