chr6-135433137-T-G

Variant names:

• chr6-135433137-T-G
• rs863225134
• NM_001134831.2:c.2156A>C

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PM1 PM2 PM5 PP3_Strong

The NM_001134831.2(AHI1):​c.2156A>C​(p.Asp719Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. D719G) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: AHI1 NM_001134831.2 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 7.48
• 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 10 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 3 uncertain in NM_001134831.2
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr6-135433137-T-C is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 217530.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.988

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
AHI1	NM_001134831.2	c.2156A>C	p.Asp719Ala	missense_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.2156A>C	p.Asp719Ala	missense_variant	Exon 16 of 29	1	NM_001134831.2	ENSP00000265602.6

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.46	D
BayesDel_noAF	Pathogenic	0.42
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.66	D;D;D;.
Eigen	Uncertain	0.33
Eigen_PC	Uncertain	0.31
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.89	.;.;D;D
M_CAP	Uncertain	0.27	D
MetaRNN	Pathogenic	0.99	D;D;D;D
MetaSVM	Uncertain	0.061	D
MutationAssessor	Pathogenic	3.8	H;H;H;H
PhyloP100		7.5
PrimateAI	Uncertain	0.56	T
PROVEAN	Pathogenic	-6.8	D;D;D;D
REVEL	Pathogenic	0.90
Sift	Uncertain	0.0030	D;D;D;D
Sift4G	Pathogenic	0.0	D;D;D;D
Polyphen		1.0	D;D;D;D
Vest4		0.98
MutPred		0.92		Gain of MoRF binding (P = 0.0703);Gain of MoRF binding (P = 0.0703);Gain of MoRF binding (P = 0.0703);Gain of MoRF binding (P = 0.0703);
MVP		0.95
MPC		0.32
ClinPred		1.0	D
GERP RS		3.4
Varity_R		0.73
gMVP		0.85
Mutation Taster		=37/63	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs863225134; hg19: chr6-135754275;