Our verdict is Benign. Variant got -14 ACMG points: 2P and 16B. PM2BP4_StrongBP6_Very_StrongBS1
The NM_001134831.2(AHI1):c.3164C>T(p.Thr1055Met) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000274 in 1,611,784 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 17/23 in silico tools predict a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Likely benign (★★).
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]
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.00871551).
BP6
Variant 6-135358133-G-A is Benign according to our data. Variant chr6-135358133-G-A is described in ClinVar as [Likely_benign]. Clinvar id is 195770.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr6-135358133-G-A is described in Lovd as [Benign].
BS1
Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.00143 (218/152306) while in subpopulation AFR AF= 0.00479 (199/41576). AF 95% confidence interval is 0.00424. There are 0 homozygotes in gnomad4. There are 113 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck.
Review Status: criteria provided, single submitter
Collection Method: clinical testing
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Apr 01, 2015
Eurofins Ntd Llc (ga)
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing
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Clinical Genetics, Academic Medical Center
Significance: Benign
Review Status: no assertion criteria provided
Collection Method: clinical testing
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not provided Benign:2
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Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center
Significance: Likely benign
Review Status: no assertion criteria provided
Collection Method: clinical testing
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Jan 19, 2021
GeneDx
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing
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Joubert syndrome 3 Benign:1
Apr 27, 2017
Illumina Laboratory Services, Illumina
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing
This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases allowed determination this variant is unlikely to cause disease. Therefore, this variant is classified as likely benign. -
Intellectual disability Benign:1
Jan 01, 2019
Centre de Biologie Pathologie Génétique, Centre Hospitalier Universitaire de Lille
Significance: Likely benign
Review Status: no assertion criteria provided
Collection Method: clinical testing
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Familial aplasia of the vermis Benign:1
Jan 23, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Likely benign
Review Status: criteria provided, single submitter