Diagnostics

Learn how our advanced genetic tests are revolutionizing health

Cone-Rod Dystrophy Panel

The Cone-Rod Dystrophy Panel is a comprehensive next-generation sequencing (NGS) panel that can be used to confirm a clinical diagnosis of cone-rody dystrophy or identify at-risk individuals.

Cone-rod is a group of related disorders that are characterized by progressive vision loss caused by degeneration of the light-sensing cells of the retina. Individuals with cone-rod dystrophy typically experience increased sensitivity to light and decreased visual acuity, which progresses to loss of color and peripheral vision, blind spots, and night blindness. The condition is progressive, and most individuals are legally blind by mid-adulthood.

Included Disorders

This panel includes genes associated with:

  • Cone-rod dystrophy
  • Achromatopsia
  • Leber congenital amaurosis
  • Retinitis pigmentosa
  • Stargardt disease
  • Vitelliform macular dystrophy
  • Bardet-Biedl syndrome
  • Juvenile macular degeneration
  • Retinitis punctata albescens

Prevalence

The prevalence of cone-rod dystrophy is 1 in 40,000 individuals (Hamel, 2007), and may be higher in certain populations.

Inheritance and Penetrance

Cone-rod dystrophy is typically inherited an autosomal recessive manner, although it may also be inherited in autosomal recessive or X-linked fashions.

Clinical Sensitivity

Disease causing variants can be identified in approximately ~50% of cone-rod dystrophy cases (Hamel, 2007). The Cone-Rod 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
  • Risk assessment for asymptomatic family members of proband with molecular diagnosis of Cone-rod dystrophy

Included genes (26)

ABCA4 CABP4 CERKL CYP4V2 MERTK PRPH2 RPGRIP1
ADAM9 CACNA1F CNGB3 GUCA1A PDE6C RAX2 SEMA4A
BEST1 CACNA2D4 CNNM4 GUCY2D PDE6H RDH5
C8ORF37 CDHR1 CRX KCNV2 PROM1 RPGR

 

Additions to the Cone-Rod Dystrophy Panel

Emerging evidence genes can also be added to the Cone-Rod Dystrophy Panel. These genes do not have a clear association with cone-rod dystrophy, but emerging evidence suggests that they may play a role in disease pathogenesis.

Emerging Evidence Genes (4)

AIPL1 PITPNM3 RIMS1 UNC119

 

References

  1. Hamel CP. Cone rod dystrophies. Orphanet J Rare Dis. 2007;2:7.