Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2BP4_Moderate
The NM_001134831.2(AHI1):c.1033T>A(p.Leu345Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000126 in 1,613,878 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
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]
Uncertain significance, criteria provided, single submitter
clinical testing
Ambry Genetics
Nov 12, 2021
The c.1033T>A (p.L345M) alteration is located in exon 8 (coding exon 6) of the AHI1 gene. This alteration results from a T to A substitution at nucleotide position 1033, causing the leucine (L) at amino acid position 345 to be replaced by a methionine (M). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -
Joubert syndrome 3 Uncertain:1
Uncertain significance, criteria provided, single submitter
clinical testing
Illumina Laboratory Services, Illumina
Jan 13, 2018
This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -
not provided Uncertain:1
Uncertain significance, criteria provided, single submitter
clinical testing
Eurofins Ntd Llc (ga)
Jun 03, 2015
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Familial aplasia of the vermis Uncertain:1
Uncertain significance, criteria provided, single submitter
clinical testing
Labcorp Genetics (formerly Invitae), Labcorp
Oct 28, 2022
This sequence change replaces leucine, which is neutral and non-polar, with methionine, which is neutral and non-polar, at codon 345 of the AHI1 protein (p.Leu345Met). This variant is present in population databases (rs200927282, gnomAD 0.03%). This variant has not been reported in the literature in individuals affected with AHI1-related conditions. ClinVar contains an entry for this variant (Variation ID: 198882). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt AHI1 protein function. 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. -
Retinal dystrophy Uncertain:1
Uncertain significance, no assertion criteria provided
clinical testing
Institute of Human Genetics, Univ. Regensburg, Univ. Regensburg
Jan 01, 2023
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not specified Benign:1
Likely benign, criteria provided, single submitter