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Bardet-Biedl Syndrome Panel

The Bardet-Biedl Panel is a comprehensive next-generation sequencing (NGS) panel that can be used to confirm a clinical diagnosis of Bardet-Biedl syndrome or identify at-risk individuals.

Bardet-Biedl syndrome is a multisystem disorder that is characterized by vision loss, obesity, intellectual disability, polydactyly, and abnormalities of the genitalia. The condition is highly variable, even among members of the same family. Vision loss is caused by deterioration of the retina (retinitis pigmentosa), and is progressive, with most individuals becoming legally blind by early adulthood.

Included Disorders

This panel includes genes associated with:

  • Bardet-Biedl syndrome
  • Joubert syndrome
  • Retinitis pigmentosa
  • Leber congenital amaurosis
  • Retinitis pigmentosa
  • Crystalline corneoretinal dystrophy
  • Retinitis punctata albescens

Prevalence

The prevalence of Bardet-Biedl syndrome is 1 in 100,000 individuals (Forsythe and Beales, 2003), although it may be higher in some populations.

Inheritance and Penetrance

Bardet-Biedl syndrome is typically inherited in an autosomal recessive fashion, and is typically fully penetrant.

Clinical Sensitivity

Disease-causing variants can be identified in 77% of Bardet-Biedl syndrome cases (Forsyth and Beales, 2003). The Bardet-Biedl Syndrome Panel includes all of the common genetic causes related to this disease.

Methodology and Analytical Sensitivity

Next-generation sequencing technology is used to test clinically relevant portions of each gene, including coding exons, adjacent flanking bases, and selected introns/noncoding variants. Pathogenic and likely pathogenic variants are confirmed by orthogonal methods. Copy number variants, including intragenic deletions and duplications are detected to a resolution of a single exon. To request analysis of a specific single exon copy number variant, please contact our Client Services team prior to ordering. Analytical sensitivity and specificity of the assay is >99%.

Indications for Testing

  • Confirmation of a clinical diagnosis
  • Retinitis pigmentosa and other anomalies
  • Risk assessment for asymptomatic family members of proband with molecular diagnosis of Bardet-Biedl syndrome

Included Genes (17)

ARL6 BBS12 BBS5 CEP290 MKS1 TTC8
BBS1 BBS2 BBS7 LZTFL1 SDCCAG8 WDPCP
BBS10 BBS4 BBS9 MKKS TRIM32

 

Additions to the Bardet-Biedl Syndrome Panel

Emerging evidence genes can also be added to the Bardet-Biedl Syndrome Panel. These genes do not have a clear association with Bardet-Biedl syndrome, but emerging evidence suggests that they may play a role in disease pathogenesis.

Emerging Evidence Genes (2)

IFT172 INPP5E

 

References

  1. Forsythe E, Beales PL. Bardet-Biedl Syndrome. 2003 Jul 14 [Updated 2015 Apr 23]. In: Pagon RA, Adam MP, Ardinger HH, et al., editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2017.