chr6-135433119-C-T

Variant names:

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_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. In-silico tool predicts a pathogenic outcome for this variant. 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

Clinical Significance

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

Conservation

PhyloP100: 7.38

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 18 ACMG points.

PVS1

Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 6-135433119-C-T is Pathogenic according to our data. Variant chr6-135433119-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 156382.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr6-135433119-C-T is described in Lovd as [Pathogenic]. Variant chr6-135433119-C-T is described in Lovd as [Pathogenic]. Variant chr6-135433119-C-T is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
AHI1	NM_001134831.2 link	c.2174G>A	p.Trp725*	stop_gained	Exon 16 of 29	ENST00000265602.11	NP_001128303.1	Q8N157-1Q8NER0

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
AHI1	ENST00000265602.11 link	c.2174G>A	p.Trp725*	stop_gained	Exon 16 of 29	1	NM_001134831.2	ENSP00000265602.6		Q8N157-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152196

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

GnomAD3 exomes

AF:

0.0000161

AC:

AN:

248916

Hom.:

AF XY:

0.00000741

AC XY:

AN XY:

135004

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 SAS 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:

0.0000109

AC:

AN:

1461384

Hom.:

Cov.:

AF XY:

0.00000413

AC XY:

AN XY:

726996

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.000227

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000630

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152196

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74338

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000169

Hom.:

Bravo

AF:

0.0000227

ExAC

AF:

0.0000248

AC:

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

- -

Genome Diagnostics Laboratory, University Medical Center Utrecht

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

- -

Clinical Genetics, Academic Medical Center

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Joubert syndrome 3

Pathogenic:3Uncertain:1

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. -

Neurology Department of Pediatrics, The Third Affiliated Hospital of Zhengzhou University

Significance: Uncertain significance

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

- -

Sep 18, 2014

Molecular Diagnostics Laboratory, Seoul National University Hospital

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

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

- -

Familial aplasia of the vermis

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. -

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

BayesDel_noAF

Pathogenic

0.66

CADD

Pathogenic

DANN

Uncertain

1.0

Eigen

Pathogenic

0.97

Eigen_PC

Pathogenic

0.85

FATHMM_MKL

Pathogenic

0.99

Vest4

0.89

ClinPred

1.0

GERP RS

5.7

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over