Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1PM2PP5_Moderate
The NM_001134831.2(AHI1):c.1355delT(p.Phe452SerfsTer2) variant causes a frameshift change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★). Variant results in nonsense mediated mRNA decay.
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]
Verdict is Pathogenic. Variant got 12 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 6-135453425-GA-G is Pathogenic according to our data. Variant chr6-135453425-GA-G is described in ClinVar as [Pathogenic]. Clinvar id is 461740.Status of the report is criteria_provided_single_submitter, 1 stars.
Review Status: criteria provided, single submitter
Collection Method: clinical testing
For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 461740). This variant has not been reported in the literature in individuals affected with AHI1-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Phe452Serfs*2) 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). -