rs863225136

Variant names:

• chr6-135433193-A-AAC
• rs863225136
• NM_001134831.2:c.2098_2099dupGT

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_001134831.2(AHI1):​c.2098_2099dupGT​(p.Tyr701PhefsTer10) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000496 in 1,612,990 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: AHI1 NM_001134831.2 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 8.72

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 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 6-135433193-A-AAC is Pathogenic according to our data. Variant chr6-135433193-A-AAC is described in ClinVar as [Pathogenic]. Clinvar id is 217533.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
AHI1	NM_001134831.2	c.2098_2099dupGT	p.Tyr701PhefsTer10	frameshift_variant	Exon 16 of 29	ENST00000265602.11	NP_001128303.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
AHI1	ENST00000265602.11	c.2098_2099dupGT	p.Tyr701PhefsTer10	frameshift_variant	Exon 16 of 29	1	NM_001134831.2	ENSP00000265602.6

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152230 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000654

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: 0.0000294

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.00000402 AC: 1 AN: 248778 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 134942

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000888

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1460760 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 726726

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000450

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152230 Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1 AN XY: 74370

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.0000654

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000294

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000712 Hom.: 0

Bravo AF: 0.0000113

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Joubert syndrome 3 Pathogenic:1

Feb 23, 2015

UW Hindbrain Malformation Research Program, University of Washington

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: research

- -

not provided Pathogenic:1

Oct 16, 2015

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.2098_2099dupGT pathogenic variant in the AHI1 gene causes a frameshift starting with codon Tyrosine 701, changes this amino acid to a Phenylalanine residue and creates a premature Stop codon at position 10 of the new reading frame, denoted p.Tyr701PhefsX10. This variant is predicted to cause loss of normal protein function either through protein truncation or nonsense-mediated mRNA decay. Therefore, c.2098_2099dupGT is considered to be a pathogenic variant. -

Familial aplasia of the vermis Pathogenic:1

Mar 14, 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.Tyr701Phefs*10) 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 (no rsID available, gnomAD 0.002%). This premature translational stop signal has been observed in individual(s) with Joubert syndrome (PMID: 26092869). ClinVar contains an entry for this variant (Variation ID: 217533). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs863225136; hg19: chr6-135754331;