11-66529817-A-G

Variant names:

• chr11-66529817-A-G
• rs113994180
• NM_024649.5:c.1340-2A>G

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PVS1 PM2 PP5

The NM_024649.5(BBS1):​c.1340-2A>G variant causes a splice acceptor, intron change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency: Genomes: not found (cov: 31)
• Consequence: BBS1 NM_024649.5 splice_acceptor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:1
• Conservation: PhyloP100: 4.21
• Publications: 1 publications found

Genes affected

BBS1 (HGNC:966): (Bardet-Biedl syndrome 1) Mutations in this gene have been observed in patients with the major form (type 1) of Bardet-Biedl syndrome. The encoded protein may play a role in eye, limb, cardiac and reproductive system development. [provided by RefSeq, Jul 2008]

ENSG00000256349 (HGNC:):

ZDHHC24 (HGNC:27387): (zinc finger DHHC-type containing 24) Predicted to enable protein-cysteine S-palmitoyltransferase activity. Predicted to be involved in peptidyl-L-cysteine S-palmitoylation and protein targeting to membrane. Predicted to be integral component of membrane. Predicted to be active in Golgi apparatus and endoplasmic reticulum. [provided by Alliance of Genome Resources, Apr 2022]

ACMG classification

Our verdict: Pathogenic. The variant received 11 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 3.3, offset of 20, new splice context is: ccatgcaccgggccttccAGaca. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 11-66529817-A-G is Pathogenic according to our data. Variant chr11-66529817-A-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 21706.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_024649.5. 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
	BBS1	NM_024649.5	MANE Select	c.1340-2A>G		splice_acceptor intron	N/A	NP_078925.3
	ZDHHC24	NM_001348571.2		c.560-329T>C		intron	N/A	NP_001335500.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	BBS1	ENST00000318312.12	TSL:1 MANE Select	c.1340-2A>G		splice_acceptor intron	N/A	ENSP00000317469.7
	ENSG00000256349	ENST00000419755.3	TSL:2	c.1451-2A>G		splice_acceptor intron	N/A	ENSP00000398526.3
	BBS1	ENST00000393994.4	TSL:1	c.953-2A>G		splice_acceptor intron	N/A	ENSP00000377563.2

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 31

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Bardet-Biedl syndrome Pathogenic:2

Oct 13, 2009

GeneReviews

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: curation

Jun 02, 2023

SN ONGC Dept of Genetics and Molecular biology Vision Research Foundation

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: research

Bardet-Biedl syndrome 1 Uncertain:1

Mar 25, 2024

Genomic Medicine Center of Excellence, King Faisal Specialist Hospital and Research Centre

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Uncertain	-0.050
CADD	Pathogenic	29
DANN	Uncertain	0.99
Eigen	Pathogenic	0.90
Eigen_PC	Pathogenic	0.70
FATHMM_MKL	Benign	0.60	D
PhyloP100		4.2
GERP RS		4.5
Mutation Taster		=2/98	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		0.97		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.24		Position offset: -20
DS_AL_spliceai		0.97		Position offset: 2

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

Other links and lift over

dbSNP: rs113994180; hg19: chr11-66297288;