rs863224814

Variant names:

• chr4-121859066-A-G
• rs863224814
• NM_176824.3:c.454T>C

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM2 PP2 PP3_Moderate

The NM_176824.3(BBS7):​c.454T>C​(p.Cys152Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,461,676 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. C152S) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: BBS7 NM_176824.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 8.93
• Publications: 0 publications found

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]

BBS7 Gene-Disease associations (from GenCC):

• Bardet-Biedl syndrome 7

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), Genomics England PanelApp
• ciliopathy

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• Bardet-Biedl syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 11 curated pathogenic missense variants (we use a threshold of 10). The gene has 1 curated benign missense variants. Gene score misZ: 1.2326 (below the threshold of 3.09). Trascript score misZ: 1.7868 (below the threshold of 3.09). GenCC associations: The gene is linked to ciliopathy, Bardet-Biedl syndrome 7, Bardet-Biedl syndrome.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.875

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_176824.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	BBS7	NM_176824.3	MANE Select	c.454T>C	p.Cys152Arg	missense	Exon 5 of 19	NP_789794.1
	BBS7	NM_018190.4		c.454T>C	p.Cys152Arg	missense	Exon 5 of 18	NP_060660.2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	BBS7	ENST00000264499.9	TSL:1 MANE Select	c.454T>C	p.Cys152Arg	missense	Exon 5 of 19	ENSP00000264499.4
	BBS7	ENST00000506636.1	TSL:1	c.454T>C	p.Cys152Arg	missense	Exon 5 of 18	ENSP00000423626.1
	BBS7	ENST00000888033.1		c.454T>C	p.Cys152Arg	missense	Exon 5 of 19	ENSP00000558092.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461676 Hom.: 0 Cov.: 30 AF XY: 0.00000550 AC XY: 4 AN XY: 727134

African (AFR) AF: 0.00 AC: 0 AN: 33470

American (AMR) AF: 0.00 AC: 0 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26128

East Asian (EAS) AF: 0.00 AC: 0 AN: 39654

South Asian (SAS) AF: 0.00 AC: 0 AN: 86254

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53416

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5764

European-Non Finnish (NFE) AF: 0.00000360 AC: 4 AN: 1111882

Other (OTH) AF: 0.0000166 AC: 1 AN: 60386

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

ClinVar submissions as Germline

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	Bardet-Biedl syndrome (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.89
BayesDel_addAF	Pathogenic	0.37	D
BayesDel_noAF	Pathogenic	0.29
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.59	D
Eigen	Pathogenic	0.81
Eigen_PC	Pathogenic	0.78
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Benign	0.81	T
M_CAP	Uncertain	0.25	D
MetaRNN	Pathogenic	0.87	D
MetaSVM	Uncertain	0.12	D
MutationAssessor	Pathogenic	3.0	M
PhyloP100		8.9
PrimateAI	Pathogenic	0.82	D
PROVEAN	Pathogenic	-4.5	D
REVEL	Pathogenic	0.75
Sift	Uncertain	0.0040	D
Sift4G	Uncertain	0.0050	D
Polyphen		1.0	D
Vest4		0.99
MutPred		0.42		Loss of catalytic residue at L153 (P = 0.0352)
MVP		0.92
MPC		0.83
ClinPred		0.99	D
GERP RS		5.4
Varity_R		0.85
gMVP		0.87
Mutation Taster		=11/89	disease causing

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

Other links and lift over

dbSNP: rs863224814; hg19: chr4-122780221;