rs886039801

chr7-33388145-G-A

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PVS1_Moderate PM2 PP3_Strong PP5_Moderate

The NM_198428.3(BBS9):c.2115+1G>A variant causes a splice donor 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. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: BBS9 NM_198428.3 splice_donor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 9.32

Genes affected

BBS9 (HGNC:30000): (Bardet-Biedl syndrome 9) This gene is downregulated by parathyroid hormone in osteoblastic cells, and therefore is thought to be involved in parathyroid hormone action in bones. The exact function of this gene has not yet been determined. Alternatively spliced transcript variants encoding different isoforms have been identified. [provided by RefSeq, Jan 2017]

ACMG classification

Verdict is Pathogenic. Variant got 10 ACMG points.

• PVS1: Splicing variant, NOT destroyed by nmd, known LOF gene, truncates exone, which is 0.057057057 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 7-33388145-G-A is Pathogenic according to our data. Variant chr7-33388145-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 266088.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BBS9	NM_198428.3	c.2115+1G>A		splice_donor_variant		ENST00000242067.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BBS9	ENST00000242067.11	c.2115+1G>A		splice_donor_variant		1	NM_198428.3	P3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

Bardet-Biedl syndrome Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jan 01, 2023	In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. ClinVar contains an entry for this variant (Variation ID: 266088). Disruption of this splice site has been observed in individual(s) with clinical features of Bardet-Biedl syndrome (PMID: 27894351, 32552793). This variant is not present in population databases (gnomAD no frequency). This sequence change affects a donor splice site in intron 19 of the BBS9 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in BBS9 are known to be pathogenic (PMID: 16380913, 20177705). -
Pathogenic, no assertion criteria provided	research	Department Of Translational Genomics (developmental Genetics Section), King Faisal Specialist Hospital & Research Centre	-	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.40
Cadd	Pathogenic	33
Dann	Uncertain	1.0
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	0.98	D
MutationTaster	Benign	1.0	D;D;D;D;D
GERP RS		5.3

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.20		Position offset: 3
DS_DL_spliceai		1.0		Position offset: -1

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

Publications

LitVar

Other links and lift over

dbSNP: rs886039801; hg19: chr7-33427757;