4-121824536-C-T

Variant names:

• chr4-121824536-C-T
• rs181687808
• NM_176824.3:c.*1324G>A

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP4_Strong BS1_Supporting

The NM_176824.3(BBS7):​c.*1324G>A variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000224 in 152,112 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: 𝑓 0.00022 (0 hom., cov: 33)
• Consequence: BBS7 NM_176824.3 3_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.686
• 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, Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
• BBS7-related ciliopathy

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

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_benign. The variant received -5 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.7).
• BS1: Variant frequency is greater than expected in population eas. GnomAd4 allele frequency = 0.000224 (34/152112) while in subpopulation EAS AF = 0.00618 (32/5174). AF 95% confidence interval is 0.0045. There are 0 homozygotes in GnomAd4. There are 24 alleles in the male GnomAd4 subpopulation. Median coverage is 33. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

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.*1324G>A		3_prime_UTR	Exon 19 of 19	NP_789794.1	Q8IWZ6-1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	BBS7	ENST00000264499.9	TSL:1 MANE Select	c.*1324G>A		3_prime_UTR	Exon 19 of 19	ENSP00000264499.4	Q8IWZ6-1
	BBS7	ENST00000888033.1		c.*1324G>A		3_prime_UTR	Exon 19 of 19	ENSP00000558092.1
	BBS7	ENST00000888034.1		c.*1324G>A		downstream_gene	N/A	ENSP00000558093.1

Frequencies

GnomAD3 genomes AF: 0.000224 AC: 34 AN: 151994 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00617

Gnomad SAS AF: 0.000208

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.000478

GnomAD4 exome Cov.: 0

GnomAD4 genome AF: 0.000224 AC: 34 AN: 152112 Hom.: 0 Cov.: 33 AF XY: 0.000323 AC XY: 24 AN XY: 74366

African (AFR) AF: 0.00 AC: 0 AN: 41514

American (AMR) AF: 0.00 AC: 0 AN: 15290

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00618 AC: 32 AN: 5174

South Asian (SAS) AF: 0.000208 AC: 1 AN: 4808

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10556

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 67982

Other (OTH) AF: 0.000473 AC: 1 AN: 2112

Alfa AF: 0.0000693 Hom.: 0

Bravo AF: 0.000257

Asia WGS AF: 0.00115 AC: 4 AN: 3478

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	Bardet-Biedl syndrome 7 (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.70
CADD	Benign	9.0
DANN	Benign	0.66
PhyloP100		0.69

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: rs181687808; hg19: chr4-122745691;