rs869025207

Variant names:

• chr4-121847492-G-C
• rs869025207
• NM_176824.3:c.949C>G

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM2 PP2 PP3_Moderate PP5_Moderate

The NM_176824.3(BBS7):​c.949C>G​(p.Leu317Val) variant causes a missense change. The variant allele was found at a frequency of 0.000000685 in 1,460,236 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 Likely pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L317Q) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: BBS7 NM_176824.3 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 3.87
• Publications: 1 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: Likely_pathogenic. The variant received 7 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, 0.909
• PP5: Variant 4-121847492-G-C is Pathogenic according to our data. Variant chr4-121847492-G-C is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 217436.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
BBS7	NM_176824.3	c.949C>G	p.Leu317Val	missense_variant	Exon 10 of 19	ENST00000264499.9	NP_789794.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
BBS7	ENST00000264499.9	c.949C>G	p.Leu317Val	missense_variant	Exon 10 of 19	1	NM_176824.3	ENSP00000264499.4
BBS7	ENST00000506636.1	c.949C>G	p.Leu317Val	missense_variant	Exon 10 of 18	1		ENSP00000423626.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460236 Hom.: 0 Cov.: 29 AF XY: 0.00000138 AC XY: 1 AN XY: 726490

African (AFR) AF: 0.0000299 AC: 1 AN: 33448

American (AMR) AF: 0.00 AC: 0 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26118

East Asian (EAS) AF: 0.00 AC: 0 AN: 39640

South Asian (SAS) AF: 0.00 AC: 0 AN: 86226

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53280

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5760

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1110708

Other (OTH) AF: 0.00 AC: 0 AN: 60336

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

Bardet-Biedl syndrome 7 Pathogenic:1

Oct 05, 2015

Department Of Medical Genetics, Faculty Of Medicine, Ege University

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: research

- -

Retinal dystrophy Pathogenic:1

Jan 01, 2022

Institute of Human Genetics, Univ. Regensburg, Univ. Regensburg

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.21
BayesDel_addAF	Pathogenic	0.46	D
BayesDel_noAF	Pathogenic	0.43
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.45	T;.
Eigen	Pathogenic	0.69
Eigen_PC	Uncertain	0.64
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.94	D;D
M_CAP	Pathogenic	0.40	D
MetaRNN	Pathogenic	0.91	D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.1	M;M
PhyloP100		3.9
PrimateAI	Uncertain	0.56	T
PROVEAN	Uncertain	-2.4	N;N
REVEL	Pathogenic	0.90
Sift	Uncertain	0.0050	D;D
Sift4G	Uncertain	0.0070	D;D
Polyphen		1.0	D;.
Vest4		0.91
MutPred		0.72		Gain of glycosylation at T319 (P = 0.0338);Gain of glycosylation at T319 (P = 0.0338);
MVP		0.99
MPC		0.28
ClinPred		0.97	D
GERP RS		4.9
Varity_R		0.32
gMVP		0.74
Mutation Taster		=25/75	disease causing (ClinVar)

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: rs869025207; hg19: chr4-122768647;