12-76346735-G-T

Variant names:

• chr12-76346735-G-T
• rs537219462
• NM_024685.4:c.1250C>A

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM2 PM5 PP2 PP3_Moderate

The NM_024685.4(BBS10):​c.1250C>A​(p.Ala417Glu) variant causes a missense change. The variant allele was found at a frequency of 0.00000124 in 1,614,098 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 Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A417T) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: BBS10 NM_024685.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.52
• Publications: 2 publications found

Genes affected

BBS10 (HGNC:26291): (Bardet-Biedl syndrome 10) This gene is a member of the Bardet-Biedl syndrome (BBS) gene family. Bardet-Biedl syndrome is an autosomal recessive disorder characterized by progressive retinal degeneration, obesity, polydactyly, renal malformation and cognitive disability. The proteins encoded by BBS gene family members are structurally diverse and the similar phenotypes exhibited by mutations in BBS gene family members is likely due to their shared roles in cilia formation and function. Many BBS proteins localize to the basal bodies, ciliary axonemes, and pericentriolar regions of cells. BBS proteins may also be involved in intracellular trafficking via microtubule-related transport. The protein encoded by this gene is likely not a ciliary protein but rather has distant sequence homology to type II chaperonins. As a molecular chaperone, this protein may affect the folding or stability of other ciliary or basal body proteins. Inhibition of this protein's expression impairs ciliogenesis in preadipocytes. Mutations in this gene cause Bardet-Biedl syndrome type 10. [provided by RefSeq, Jan 2010]

BBS10 Gene-Disease associations (from GenCC):

• Bardet-Biedl syndrome 10

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

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

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ENSG00000306428 (HGNC:):

ACMG classification

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr12-76346736-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 2152157.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 24 curated pathogenic missense variants (we use a threshold of 10). The gene has 5 curated benign missense variants. Trascript score misZ: 0.43507 (below the threshold of 3.09). GenCC associations: The gene is linked to Bardet-Biedl syndrome 10, ciliopathy, Bardet-Biedl syndrome.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.922

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_024685.4. 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
	BBS10	NM_024685.4	MANE Select	c.1250C>A	p.Ala417Glu	missense	Exon 2 of 2	NP_078961.3

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	BBS10	ENST00000650064.2	MANE Select	c.1250C>A	p.Ala417Glu	missense	Exon 2 of 2	ENSP00000497413.1
	ENSG00000306428	ENST00000818399.1		n.175-422G>T		intron	N/A
	ENSG00000306428	ENST00000818400.1		n.202-422G>T		intron	N/A

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152180 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: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461800 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 727200

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

African (AFR) AF: 0.00 AC: 0 AN: 33476

American (AMR) AF: 0.00 AC: 0 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26132

East Asian (EAS) AF: 0.00 AC: 0 AN: 39688

South Asian (SAS) AF: 0.00 AC: 0 AN: 86252

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53416

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

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111952

Other (OTH) AF: 0.00 AC: 0 AN: 60394

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152298 Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1 AN XY: 74476

African (AFR) AF: 0.00 AC: 0 AN: 41572

American (AMR) AF: 0.0000654 AC: 1 AN: 15302

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3466

East Asian (EAS) AF: 0.00 AC: 0 AN: 5184

South Asian (SAS) AF: 0.00 AC: 0 AN: 4826

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10612

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68018

Other (OTH) AF: 0.00 AC: 0 AN: 2112

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Inborn genetic diseases Uncertain:1

Oct 12, 2015

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.87
BayesDel_addAF	Pathogenic	0.41	D
BayesDel_noAF	Pathogenic	0.35
CADD	Uncertain	26
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.90	D
Eigen	Pathogenic	0.75
Eigen_PC	Pathogenic	0.70
FATHMM_MKL	Uncertain	0.88	D
LIST_S2	Benign	0.75	T
M_CAP	Benign	0.078	D
MetaRNN	Pathogenic	0.92	D
MetaSVM	Uncertain	0.69	D
MutationAssessor	Uncertain	2.9	M
PhyloP100		5.5
PrimateAI	Uncertain	0.60	T
PROVEAN	Uncertain	-4.2	D
REVEL	Pathogenic	0.86
Sift	Uncertain	0.0020	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.93
MutPred		0.77		Gain of disorder (P = 0.0284)
MVP		0.94
MPC		0.39
ClinPred		0.99	D
GERP RS		5.1
Varity_R		0.89
gMVP		0.91
Mutation Taster		=70/30	polymorphism

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: rs537219462; hg19: chr12-76740515;