6-135497187-C-T

Variant names:

• chr6-135497187-C-T
• rs145372075
• NM_001134831.2:c.-140+1G>A

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1 PM2

The NM_001134831.2(AHI1):​c.-140+1G>A variant causes a splice donor, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000131 in 152,180 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: 𝑓 0.000013 (0 hom., cov: 33)
• Consequence: AHI1 NM_001134831.2 splice_donor, intron
• Scores: Splicing: ADA: 0.9998
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.875
• Publications: 1 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-DT (HGNC:32526): (AHI1 divergent transcript)

ACMG classification

Our verdict: Pathogenic. The variant received 10 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
AHI1	NM_001134831.2	c.-140+1G>A		splice_donor_variant, intron_variant	Intron 2 of 28	ENST00000265602.11	NP_001128303.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
AHI1	ENST00000265602.11	c.-140+1G>A		splice_donor_variant, intron_variant	Intron 2 of 28	1	NM_001134831.2	ENSP00000265602.6

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152180 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000655

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: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 0

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152180 Hom.: 0 Cov.: 33 AF XY: 0.0000135 AC XY: 1 AN XY: 74334

African (AFR) AF: 0.0000241 AC: 1 AN: 41450

American (AMR) AF: 0.0000655 AC: 1 AN: 15274

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5196

South Asian (SAS) AF: 0.00 AC: 0 AN: 4828

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10612

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68028

Other (OTH) AF: 0.00 AC: 0 AN: 2094

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000416

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.52
CADD	Benign	22
DANN	Benign	0.87
PhyloP100		0.88
PromoterAI		0.0049	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.76
SpliceAI score (max)		0.0		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: rs145372075; hg19: chr6-135818325;