7-33257238-C-T

Variant names:

• chr7-33257238-C-T
• rs781174906
• NM_198428.3:c.445C>T

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_198428.3(BBS9):​c.445C>T​(p.Arg149*) variant causes a stop gained, splice region change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000062 in 1,452,672 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 1/1 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000062 (0 hom.)
• Consequence: BBS9 NM_198428.3 stop_gained, splice_region
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 7.91

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 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 7-33257238-C-T is Pathogenic according to our data. Variant chr7-33257238-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 523079.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr7-33257238-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
BBS9	NM_198428.3	c.445C>T	p.Arg149*	stop_gained, splice_region_variant	Exon 6 of 23	ENST00000242067.11	NP_940820.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
BBS9	ENST00000242067.11	c.445C>T	p.Arg149*	stop_gained, splice_region_variant	Exon 6 of 23	1	NM_198428.3	ENSP00000242067.6

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.0000120 AC: 3 AN: 250306 Hom.: 0 AF XY: 0.0000222 AC XY: 3 AN XY: 135284

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000265

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000620 AC: 9 AN: 1452672 Hom.: 0 Cov.: 29 AF XY: 0.0000111 AC XY: 8 AN XY: 722838

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000814

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.0000247 AC: 3

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Bardet-Biedl syndrome 9 Pathogenic:2

Dec 18, 2017

Genomic Research Center, Shahid Beheshti University of Medical Sciences

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Nov 02, 2023

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Bardet-Biedl syndrome Pathogenic:1

Jun 01, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Arg149*) in the BBS9 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in BBS9 are known to be pathogenic (PMID: 16380913, 20177705). This variant is present in population databases (rs781174906, gnomAD 0.003%). This premature translational stop signal has been observed in individual(s) with Bardet–Biedl syndrome (PMID: 33777945). ClinVar contains an entry for this variant (Variation ID: 523079). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.66
CADD	Pathogenic	40
DANN	Uncertain	1.0
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.91
FATHMM_MKL	Pathogenic	0.99	D
Vest4		0.54
GERP RS		5.8

Splicing

Name	Calibrated prediction	Score	Prediction
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

Publications

LitVar

Other links and lift over

dbSNP: rs781174906; hg19: chr7-33296850;