16-56519791-G-A

Variant names:

• chr16-56519791-G-A
• rs121908175
• NM_031885.5:c.72C>T

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 2P and 3B. PM2 BP4_Moderate BP7

The NM_031885.5(BBS2):​c.72C>T​(p.Tyr24Tyr) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,390 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 (no stars).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: BBS2 NM_031885.5 synonymous
• Clinical Significance: Uncertain significance no assertion criteria provided U:1
• Conservation: PhyloP100: 2.80
• Publications: 0 publications found

Genes affected

BBS2 (HGNC:967): (Bardet-Biedl syndrome 2) This gene is a member of the Bardet-Biedl syndrome (BBS) gene family. Bardet-Biedl syndrome is an autosomal recessive disorder characterized by severe pigmentary retinopathy, 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 forms a multiprotein BBSome complex with seven other BBS proteins.[provided by RefSeq, Oct 2014]

BBS2 Gene-Disease associations (from GenCC):

• Bardet-Biedl syndrome 2

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, G2P, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Myriad Women’s Health
• BBS2-related ciliopathy

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• retinitis pigmentosa 74

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae)
• retinitis pigmentosa

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Bardet-Biedl syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_benign. The variant received -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.41).
• BP7: Synonymous conserved (PhyloP=2.8 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_031885.5. 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
	BBS2	NM_031885.5	MANE Select	c.72C>T	p.Tyr24Tyr	synonymous	Exon 1 of 17	NP_114091.4
	BBS2	NM_001377456.1		c.72C>T	p.Tyr24Tyr	synonymous	Exon 1 of 18	NP_001364385.1	Q9BXC9
	BBS2	NR_165293.1		n.234C>T		non_coding_transcript_exon	Exon 1 of 17

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	BBS2	ENST00000245157.11	TSL:1 MANE Select	c.72C>T	p.Tyr24Tyr	synonymous	Exon 1 of 17	ENSP00000245157.5	Q9BXC9
	BBS2	ENST00000565781.6	TSL:1	n.131+166C>T		intron	N/A
	BBS2	ENST00000682188.1		c.72C>T	p.Tyr24Tyr	synonymous	Exon 1 of 17	ENSP00000507655.1	A0A804HJV0

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461390 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727038

African (AFR) AF: 0.00 AC: 0 AN: 33460

American (AMR) AF: 0.00 AC: 0 AN: 44690

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26110

East Asian (EAS) AF: 0.00 AC: 0 AN: 39686

South Asian (SAS) AF: 0.00 AC: 0 AN: 86234

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53322

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111786

Other (OTH) AF: 0.00 AC: 0 AN: 60336

GnomAD4 genome Cov.: 32

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: no assertion criteria provided

Pathogenic	VUS	Benign	Condition
-	1	-	Bardet-Biedl syndrome 2 (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.41
CADD	Benign	16
DANN	Benign	0.96
PhyloP100		2.8
PromoterAI		0.025	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs121908175; hg19: chr16-56553703;