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Congenital Cataracts Panel

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

Congenital cataracts are lens opacities that are present from birth. Hereditary congenital cataracts are caused by pathogenic changes in genes that encode proteins related to cell transparency. Congenital cataracts may appear in isolation, or as part of a syndrome, and the degree of vision loss is variable between individuals.

Included Disorders

This panel includes genes associated with:

  • Congenital Cataracts
  • Sengers syndrome
  • Axenfeld-Rieger syndrome
  • Lowe syndrome
  • Nance-Horan syndrome
  • Branchio-oto-renal syndrome
  • Marinesco-Sjogren syndrome
  • EDICT syndrome
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    Prevalence

    The prevalence of congenital cataract is estimated to be 1-15 in 10,000, with 1/4 to 1/3 of cases considered to be hereditary (Yi et al, 2011).

    Inheritance and Penetrance

    Congenital cataracts are inherited in autosomal dominant, autosomal recessive, and X-linked fashions. Penetrance is typically high.

    Clinical Sensitivity

    Pathogenic variants can be identified in approximately 40% of congenital cataract cases (Reis et al, 2013; Sun et al 2011). The Congenital Cataracts 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 congenital cataracts

    Included Genes (38)

    AGK CRYBB2 FAM126A HSF4 PITX2
    BCOR CRYBB3 FOXC1 MAF PITX3
    BFSP1 CRYGC FOXE3 MIP PXDN
    BFSP2 CRYGD FYCO1 MIR184 SIL1
    CRYAA CRYGS GALK1 NHS SLC33A1
    CRYAB CTDP1 GCNT2 OCRL VSX2
    CRYBA1 EPHA2 GJA3 P3H2
    CRYBB1 EYA1 GJA8 PAX6

     

    Additions to the Congenital Cataracts Panel

    Emerging evidence genes can also be added to the Congenital Cataracts Panel. These genes do not have a clear association with congenital cataracts, but emerging evidence suggests that they may play a role in disease pathogenesis:

    Emerging Evidence Genes (6)

    CHMP4B CRYBA4 CRYGB LIM2 TDRD7 VIM

     

    References

    1. Yi J, Yun J, Li ZK, Xu CT, Pan BR. Epidemiology and molecular genetics of congenital cataracts. Int J Ophthalmol. 2011;4(4):422-32.
    2. Reis LM, Tyler RC, Muheisen S, et al. Whole exome sequencing in dominant cataract identifies a new causative factor, CRYBA2, and a variety of novel alleles in known genes. Hum Genet. 2013;132(7):761-70.
    3. Sun W, Xiao X, Li S, Guo X, Zhang Q. Mutation analysis of 12 genes in Chinese families with congenital cataracts. Mol Vis. 2011;17:2197-206.