NM_001134831.2:c.1260G>A

Variant summary

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

The NM_001134831.2(AHI1):​c.1260G>A​(p.Trp420*) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000331 in 1,600,720 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 Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000036 ( 0 hom. )

Consequence

AHI1
NM_001134831.2 stop_gained

Scores

5
1
1

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:6

Conservation

PhyloP100: 7.56

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 6-135455818-C-T is Pathogenic according to our data. Variant chr6-135455818-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 217543.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.1260G>A p.Trp420* stop_gained Exon 10 of 29 ENST00000265602.11 NP_001128303.1 Q8N157-1Q8NER0

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
AHI1ENST00000265602.11 linkc.1260G>A p.Trp420* stop_gained Exon 10 of 29 1 NM_001134831.2 ENSP00000265602.6 Q8N157-1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152146
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:
0.0000130
AC:
3
AN:
230596
AF XY:
0.00000803
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000292
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000359
AC:
52
AN:
1448574
Hom.:
0
Cov.:
30
AF XY:
0.0000431
AC XY:
31
AN XY:
719328
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33256
American (AMR)
AF:
0.0000230
AC:
1
AN:
43500
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25724
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39424
South Asian (SAS)
AF:
0.00
AC:
0
AN:
83756
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52780
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5742
European-Non Finnish (NFE)
AF:
0.0000462
AC:
51
AN:
1104496
Other (OTH)
AF:
0.00
AC:
0
AN:
59896
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.481
Heterozygous variant carriers
0
4
8
12
16
20
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
4
8
12
16
20
<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:
152146
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74330
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41440
American (AMR)
AF:
0.00
AC:
0
AN:
15272
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5202
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4820
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10604
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68018
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
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:
0.0000386
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:6
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Joubert syndrome 3 Pathogenic:3
-
Genomics England Pilot Project, Genomics England
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Oct 31, 2018
Fulgent Genetics, Fulgent Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
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

- -

Joubert syndrome Pathogenic:1
Nov 18, 2023
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.Trp420*) 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 (no rsID available, gnomAD 0.003%). This premature translational stop signal has been observed in individual(s) with Joubert syndrome (PMID: 26092869). ClinVar contains an entry for this variant (Variation ID: 217543). For these reasons, this variant has been classified as Pathogenic. -

not provided Pathogenic:1
May 31, 2023
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss of function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 34758253, 31589614, 28442542, 29186038, 15322546, 16453322, 26092869) -

Joubert syndrome and related disorders Pathogenic:1
Dec 26, 2024
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: AHI1 c.1260G>A (p.Trp420X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. The variant allele was found at a frequency of 1.3e-05 in 230596 control chromosomes. c.1260G>A has been reported in the literature in individuals affected with Joubert Syndrome And Related Disorders (e.g. Bachmann-Gagescu_2015). To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication have been ascertained in the context of this evaluation (PMID: 26092869). ClinVar contains an entry for this variant (Variation ID: 217543). Based on the evidence outlined above, the variant was classified as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.57
D
BayesDel_noAF
Pathogenic
0.66
CADD
Pathogenic
39
DANN
Uncertain
1.0
Eigen
Pathogenic
0.95
Eigen_PC
Pathogenic
0.85
FATHMM_MKL
Pathogenic
0.98
D
PhyloP100
7.6
Vest4
0.94
GERP RS
5.7
Mutation Taster
=0/200
disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs863225143; hg19: chr6-135776956; API