chr4-121833309-TCTGGAA-T

Position:

• chr4-121833309-TCTGGAA-T

Variant summary

Our verdict is Pathogenic. Variant got 13 ACMG points: 13P and 0B. PM2 PM4 PP3 PP5_Very_Strong

The NM_176824.3(BBS7):​c.1592_1597del​(p.Val531_Pro532del) variant causes a inframe deletion change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000867 in 1,613,924 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000089 (0 hom.)
• Consequence: BBS7 NM_176824.3 inframe_deletion
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: 9.80

Genes affected

BBS7 (HGNC:18758): (Bardet-Biedl syndrome 7) This gene encodes one of eight proteins that form the BBSome complex containing BBS1, BBS2, BBS4, BBS5, BBS7, BBS8, BBS9 and BBIP10. The BBSome complex is believed to recruit Rab8(GTP) to the primary cilium and promote ciliogenesis. The BBSome complex assembly is mediated by a complex composed of three chaperonin-like BBS proteins (BBS6, BBS10, and BBS12) and CCT/TRiC family chaperonins. Mutations in this gene are implicated in Bardet-Biedl syndrome, a genetic disorder whose symptoms include obesity, retinal degeneration, polydactyly and nephropathy; however, mutations in this gene and the BBS8 gene are thought to play a minor role and mutations in chaperonin-like BBS genes are found to be a major contributor to disease development in a multiethnic Bardet-Biedl syndrome patient population. Two transcript variants encoding distinct isoforms have been identified for this gene.[provided by RefSeq, Oct 2014]

ACMG classification

Verdict is Pathogenic. Variant got 13 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM4: Nonframeshift variant in NON repetitive region in NM_176824.3.
• PP3: No computational evidence supports a deleterious effect, but strongly conserved according to phyloP
• PP5: Variant 4-121833309-TCTGGAA-T is Pathogenic according to our data. Variant chr4-121833309-TCTGGAA-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 30680.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr4-121833309-TCTGGAA-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BBS7	NM_176824.3	c.1592_1597del	p.Val531_Pro532del	inframe_deletion	15/19	ENST00000264499.9	NP_789794.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BBS7	ENST00000264499.9	c.1592_1597del	p.Val531_Pro532del	inframe_deletion	15/19	1	NM_176824.3	ENSP00000264499	P1
BBS7	ENST00000506636.1	c.1592_1597del	p.Val531_Pro532del	inframe_deletion	15/18	1		ENSP00000423626

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152210 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000207

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000159 AC: 4 AN: 251336 Hom.: 0 AF XY: 0.0000221 AC XY: 3 AN XY: 135830

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: 0.000131

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000889 AC: 13 AN: 1461714 Hom.: 0 AF XY: 0.0000165 AC XY: 12 AN XY: 727164

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: 0.000151

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152210 Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1 AN XY: 74368

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.000207

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Bardet-Biedl syndrome 7 Pathogenic:3

Pathogenic, no assertion criteria provided	clinical testing	Dr.Nikuei Genetic Center	May 22, 2024	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Apr 29, 2023	- -
Pathogenic, no assertion criteria provided	literature only	OMIM	Sep 21, 2011	- -

Bardet-Biedl syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 29, 2022

For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 30680). This variant is also known as 533del2aa. This variant has been observed in individual(s) with Bardet-Biedl syndrome (PMID: 21937992, 28761321). It has also been observed to segregate with disease in related individuals. This variant is present in population databases (rs587777836, gnomAD 0.01%). This variant, c.1592_1597del, results in the deletion of 2 amino acid(s) of the BBS7 protein (p.Val531_Pro532del), but otherwise preserves the integrity of the reading frame. -

Computational scores

Source: dbNSFP v4.3

Splicing

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

Publications

LitVar

Other links and lift over

dbSNP: rs587777836; hg19: chr4-122754464;