rs201938124

chr7-33367863-G-Achr7-33367863-G-Cchr7-33367863-G-T

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PVS1_Moderate PM2 PP3_Strong PP5_Very_Strong

The NM_198428.3(BBS9):c.1789+1G>A variant causes a splice donor change. The variant allele was found at a frequency of 0.00000342 in 1,460,808 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 2/2 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: BBS9 NM_198428.3 splice_donor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:7
• Conservation: PhyloP100: 6.99

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 16 ACMG points.

• PVS1: Splicing variant, NOT destroyed by nmd, known LOF gene, truncates exone, which is 0.03566066 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. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 7-33367863-G-A is Pathogenic according to our data. Variant chr7-33367863-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 2656.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BBS9	NM_198428.3	c.1789+1G>A		splice_donor_variant		ENST00000242067.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BBS9	ENST00000242067.11	c.1789+1G>A		splice_donor_variant		1	NM_198428.3	P3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1460808 Hom.: 0 Cov.: 30 AF XY: 0.00000413 AC XY: 3 AN XY: 726776

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:7

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Bardet-Biedl syndrome 9 Pathogenic:4

Pathogenic, no assertion criteria provided	literature only	OMIM	Dec 01, 2005	- -
Pathogenic, criteria provided, single submitter	clinical testing	Fulgent Genetics, Fulgent Genetics	Mar 11, 2022	- -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Jan 03, 2022	- -
Pathogenic, no assertion criteria provided	clinical testing	Biochemical Molecular Genetic Laboratory, King Abdulaziz Medical City	Oct 11, 2020	- -

not provided Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Oct 25, 2016	The c.1789+1G>A pathogenic variant in the BBS9 gene has been reported previously in the homozygous state in an individual with Bardet-Biedl syndrome (Nishimura et al., 2005). This splice site variant destroys the canonical splice donor site in intron 17. It is predicted to cause abnormal gene splicing, either leading to an abnormal message that is subject to nonsense-mediated mRNA decay, or to an abnormal protein product if the message is used for protein translation. The c.1789+1G>A variant was not observed in approximately 6500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. We interpret c.1789+1G>A as a pathogenic variant. -
Pathogenic, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Apr 23, 2015	- -

Bardet-Biedl syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Oct 22, 2023

This sequence change affects a donor splice site in intron 17 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). This variant is not present in population databases (gnomAD no frequency). Disruption of this splice site has been observed in individual(s) with Bardet–Biedl syndrome (PMID: 16380913, 32165602). ClinVar contains an entry for this variant (Variation ID: 2656). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.42
Cadd	Pathogenic	34
Dann	Uncertain	1.0
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	0.97	D
MutationTaster	Benign	1.0	D;D;D;D;D
GERP RS		5.5

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.99		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: rs201938124; hg19: chr7-33407475; COSMIC: COSV54176338;