chr4-122743042-AG-A

Variant names:

• chr4-122743042-AG-A
• rs1553941404
• NM_152618.3:c.1151delG

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_152618.3(BBS12):​c.1151delG​(p.Ser384ThrfsTer21) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000248 in 1,614,152 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: BBS12 NM_152618.3 frameshift
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:5 U:1
• Conservation: PhyloP100: -0.0280
• Publications: 0 publications found

Genes affected

BBS12 (HGNC:26648): (Bardet-Biedl syndrome 12) The protein encoded by this gene is part of a complex that is involved in membrane trafficking. The encoded protein is a molecular chaperone that aids in protein folding upon ATP hydrolysis. This protein also plays a role in adipocyte differentiation. Defects in this gene are a cause of Bardet-Biedl syndrome type 12. Two transcript variants encoding the same protein have been found for this gene. [provided by RefSeq, May 2010]

BBS12 Gene-Disease associations (from GenCC):

• Bardet-Biedl syndrome 12

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, G2P, Ambry Genetics, Myriad Women’s Health
• ciliopathy

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

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 18 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 101 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 4-122743042-AG-A is Pathogenic according to our data. Variant chr4-122743042-AG-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 550386.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_152618.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	BBS12	NM_152618.3	MANE Select	c.1151delG	p.Ser384ThrfsTer21	frameshift	Exon 2 of 2	NP_689831.2
	BBS12	NM_001178007.2		c.1151delG	p.Ser384ThrfsTer21	frameshift	Exon 3 of 3	NP_001171478.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	BBS12	ENST00000314218.8	TSL:1 MANE Select	c.1151delG	p.Ser384ThrfsTer21	frameshift	Exon 2 of 2	ENSP00000319062.3
	BBS12	ENST00000542236.5	TSL:2	c.1151delG	p.Ser384ThrfsTer21	frameshift	Exon 3 of 3	ENSP00000438273.1

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152270 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000654

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.000478

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461882 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727242

African (AFR) AF: 0.0000597 AC: 2 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53414

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1112008

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152270 Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1 AN XY: 74400

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 41478

American (AMR) AF: 0.0000654 AC: 1 AN: 15290

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3468

East Asian (EAS) AF: 0.00 AC: 0 AN: 5202

South Asian (SAS) AF: 0.00 AC: 0 AN: 4834

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10630

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68046

Other (OTH) AF: 0.000478 AC: 1 AN: 2094

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000756

ClinVar

ClinVar submissions as Germline

Significance: Pathogenic/Likely pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
3	-	-	Bardet-Biedl syndrome 12 (3)
1	1	-	not provided (2)
1	-	-	Bardet-Biedl syndrome (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		-0.028
Mutation Taster		=2/198	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: rs1553941404; hg19: chr4-123664197;