4-122741921-A-G

Position:

• chr4-122741921-A-G

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_152618.3(BBS12):​c.29A>G​(p.Lys10Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 16/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: BBS12 NM_152618.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.08

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]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.059300452).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BBS12	NM_152618.3	c.29A>G	p.Lys10Arg	missense_variant	2/2	ENST00000314218.8	NP_689831.2
BBS12	NM_001178007.2	c.29A>G	p.Lys10Arg	missense_variant	3/3		NP_001171478.1
BBS12	XM_011531680.3	c.29A>G	p.Lys10Arg	missense_variant	2/2		XP_011529982.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BBS12	ENST00000314218.8	c.29A>G	p.Lys10Arg	missense_variant	2/2	1	NM_152618.3	ENSP00000319062	P1
BBS12	ENST00000542236.5	c.29A>G	p.Lys10Arg	missense_variant	3/3	2		ENSP00000438273	P1
BBS12	ENST00000433287.1	c.29A>G	p.Lys10Arg	missense_variant	3/3	2		ENSP00000398912

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Bardet-Biedl syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Mar 24, 2022

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The arginine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. This variant has not been reported in the literature in individuals affected with BBS12-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces lysine, which is basic and polar, with arginine, which is basic and polar, at codon 10 of the BBS12 protein (p.Lys10Arg). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.068
BayesDel_addAF	Benign	-0.25	T
BayesDel_noAF	Benign	-0.60
CADD	Benign	13
DANN	Benign	0.84
DEOGEN2	Benign	0.029	T;T;.
Eigen	Benign	-1.2
Eigen_PC	Benign	-0.98
FATHMM_MKL	Benign	0.75	D
LIST_S2	Benign	0.42	T;.;T
M_CAP	Benign	0.013	T
MetaRNN	Benign	0.059	T;T;T
MetaSVM	Benign	-0.92	T
MutationAssessor	Benign	0.38	N;N;.
MutationTaster	Benign	1.0	N;N
PrimateAI	Benign	0.35	T
PROVEAN	Benign	-0.19	N;N;N
REVEL	Benign	0.063
Sift	Benign	0.72	T;T;T
Sift4G	Benign	0.96	T;T;T
Polyphen		0.0010	B;B;.
Vest4		0.068
MutPred		0.24		Loss of methylation at K10 (P = 0.0211);Loss of methylation at K10 (P = 0.0211);Loss of methylation at K10 (P = 0.0211);
MVP		0.87
MPC		0.070
ClinPred		0.024	T
GERP RS		-2.4
Varity_R		0.035
gMVP		0.087

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr4-123663076; COSMIC: COSV105195294;