rs145372075

chr6-135497187-C-Achr6-135497187-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 10P and 5B. PVS1 PP3_Moderate BP6 BS2

The NM_001134831.2(AHI1):c.-140+1G>T variant causes a splice donor change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00275 in 152,296 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.0028 (2 hom., cov: 33)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: AHI1 NM_001134831.2 splice_donor
• Scores: Splicing: ADA: 0.9998
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:2
• Conservation: PhyloP100: 0.875

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 5 ACMG points.

• PVS1: Splicing variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. Scorers claiming Benign: max_spliceai.
• BP6: Variant 6-135497187-C-A is Benign according to our data. Variant chr6-135497187-C-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 235687.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=2, Uncertain_significance=1}.
• BS2: High Homozygotes in GnomAd at 2 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
AHI1	NM_001134831.2	c.-140+1G>T		splice_donor_variant		ENST00000265602.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
AHI1	ENST00000265602.11	c.-140+1G>T		splice_donor_variant		1	NM_001134831.2	P2

Frequencies

GnomAD3 genomes AF: 0.00273 AC: 416 AN: 152178 Hom.: 2 Cov.: 33

Gnomad AFR AF: 0.00936

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00118

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000207

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000735

Gnomad OTH AF: 0.00191

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 18 Hom.: 0 Cov.: 0 AF XY: 0.00 AC XY: 0 AN XY: 16

Gnomad4 ASJ exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

GnomAD4 genome AF: 0.00275 AC: 419 AN: 152296 Hom.: 2 Cov.: 33 AF XY: 0.00247 AC XY: 184 AN XY: 74462

Gnomad4 AFR AF: 0.00941

Gnomad4 AMR AF: 0.00118

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.000207

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000735

Gnomad4 OTH AF: 0.00189

Alfa AF: 0.0000696 Hom.: 0

Bravo AF: 0.00311

Asia WGS AF: 0.00115 AC: 4 AN: 3478

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Center for Pediatric Genomic Medicine, Children's Mercy Hospital and Clinics

Aug 26, 2015

- -

not specified Benign:1

Likely benign, criteria provided, single submitter

clinical testing

GeneDx

Sep 14, 2017

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

AHI1-related disorder Benign:1

Likely benign, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

May 17, 2022

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.52
Cadd	Benign	22
Dann	Benign	0.87
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.75
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

Other links and lift over

dbSNP: rs145372075; hg19: chr6-135818325;