4-122743466-G-C

Variant names:

• chr4-122743466-G-C
• rs776730549
• NM_152618.3:c.1574G>C

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PM1 PM2 PM5 PP3_Strong

The NM_152618.3(BBS12):​c.1574G>C​(p.Arg525Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,202 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R525H) has been classified as Likely pathogenic.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
• Consequence: BBS12 NM_152618.3 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 8.99
• Publications: 11 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 10 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 9 uncertain in NM_152618.3
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr4-122743466-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 220303.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.957

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.1574G>C	p.Arg525Pro	missense	Exon 2 of 2	NP_689831.2
	BBS12	NM_001178007.2		c.1574G>C	p.Arg525Pro	missense	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.1574G>C	p.Arg525Pro	missense	Exon 2 of 2	ENSP00000319062.3
	BBS12	ENST00000542236.5	TSL:2	c.1574G>C	p.Arg525Pro	missense	Exon 3 of 3	ENSP00000438273.1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152202 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

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: 0.00

GnomAD4 exome Cov.: 35

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152202 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 74356

African (AFR) AF: 0.0000241 AC: 1 AN: 41448

American (AMR) AF: 0.00 AC: 0 AN: 15284

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

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

South Asian (SAS) AF: 0.00 AC: 0 AN: 4832

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10604

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68040

Other (OTH) AF: 0.00 AC: 0 AN: 2094

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.96
BayesDel_addAF	Pathogenic	0.40	D
BayesDel_noAF	Pathogenic	0.33
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.72	D
Eigen	Uncertain	0.44
Eigen_PC	Uncertain	0.36
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Benign	0.76	T
M_CAP	Uncertain	0.10	D
MetaRNN	Pathogenic	0.96	D
MetaSVM	Uncertain	0.19	D
MutationAssessor	Uncertain	2.8	M
PhyloP100		9.0
PrimateAI	Uncertain	0.59	T
PROVEAN	Pathogenic	-4.8	D
REVEL	Pathogenic	0.74
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.92
MutPred		0.79		Loss of helix (P = 0.028)
MVP		0.88
MPC		0.55
ClinPred		1.0	D
GERP RS		4.9
Varity_R		0.92
gMVP		0.92
Mutation Taster		=34/66	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: rs776730549; hg19: chr4-123664621;