rs121434349

Variant names:

• chr6-135455775-G-A
• rs121434349
• NM_001134831.2:c.1303C>T

Your query was ambiguous. Multiple possible variants found:

• chr6-135455775-G-A
• chr6-135455775-G-T

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_001134831.2(AHI1):​c.1303C>T​(p.Arg435*) variant causes a stop gained change. The variant allele was found at a frequency of 0.00000276 in 1,450,734 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★). Synonymous variant affecting the same amino acid position (i.e. R435R) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000028 (0 hom.)
• Consequence: AHI1 NM_001134831.2 stop_gained
• Clinical Significance: Pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 4.45
• Publications: 4 publications found

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]

AHI1 Gene-Disease associations (from GenCC):

• Joubert syndrome 3

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, ClinGen, Laboratory for Molecular Medicine, Ambry Genetics
• Joubert syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• Joubert syndrome with ocular defect

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• retinitis pigmentosa

  Inheritance: AR, AD Classification: SUPPORTIVE, LIMITED Submitted by: Ambry Genetics, Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 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 6-135455775-G-A is Pathogenic according to our data. Variant chr6-135455775-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 2011.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001134831.2. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	AHI1	NM_001134831.2	MANE Select	c.1303C>T	p.Arg435*	stop_gained	Exon 10 of 29	NP_001128303.1
	AHI1	NM_001134830.2		c.1303C>T	p.Arg435*	stop_gained	Exon 8 of 27	NP_001128302.1
	AHI1	NM_001350503.2		c.1303C>T	p.Arg435*	stop_gained	Exon 10 of 29	NP_001337432.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	AHI1	ENST00000265602.11	TSL:1 MANE Select	c.1303C>T	p.Arg435*	stop_gained	Exon 10 of 29	ENSP00000265602.6
	AHI1	ENST00000367800.8	TSL:1	c.1303C>T	p.Arg435*	stop_gained	Exon 8 of 27	ENSP00000356774.4
	AHI1	ENST00000457866.6	TSL:1	c.1303C>T	p.Arg435*	stop_gained	Exon 9 of 28	ENSP00000388650.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000853 AC: 2 AN: 234460 AF XY: 0.00000790

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 FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000190

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000276 AC: 4 AN: 1450734 Hom.: 0 Cov.: 30 AF XY: 0.00000555 AC XY: 4 AN XY: 720616

African (AFR) AF: 0.00 AC: 0 AN: 33282

American (AMR) AF: 0.00 AC: 0 AN: 43756

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25804

East Asian (EAS) AF: 0.00 AC: 0 AN: 39468

South Asian (SAS) AF: 0.00 AC: 0 AN: 84030

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52898

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5734

European-Non Finnish (NFE) AF: 0.00000271 AC: 3 AN: 1105846

Other (OTH) AF: 0.0000167 AC: 1 AN: 59916

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000187 Hom.: 0

Bravo AF: 0.00000378

ExAC AF: 0.00000828 AC: 1

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

Joubert syndrome Pathogenic:1

Feb 27, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

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: 2011). This premature translational stop signal has been observed in individual(s) with Joubert syndrome (PMID: 15322546, 18054307). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This sequence change creates a premature translational stop signal (p.Arg435*) 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).

Joubert syndrome 3 Pathogenic:1

Sep 01, 2004

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.62
CADD	Pathogenic	38
DANN	Uncertain	1.0
Eigen	Pathogenic	0.69
Eigen_PC	Uncertain	0.55
FATHMM_MKL	Pathogenic	0.97	D
PhyloP100		4.4
Vest4		0.88
GERP RS		4.6
Mutation Taster		=0/200	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs121434349; hg19: chr6-135776913; COSMIC: COSV55624427;