Molecular Genetics Achromatopsia, CNGA3/CNGB3, Sequencing

Achromatopsia is characterized by reduced visual acuity (<0.1 or 20/200), nystagmus, sensitivity to light, small central scotoma, eccentric fixation and reduced or complete loss of color discrimination.  The diagnosis is based on color vision testing, electroretinography, and fundus examination.  Known genetic causes of this disorder are mutations in the cone cell subunits alpha, CNGA3, and beta, CNGB3.  Mutations in CNGB3 account for 50% of the affected individuals^1,2, and 25% harbor mutations in CNGA3^3,4.

Reasons for Referral:

• Confirmation of clinical diagnosis in patients with classical or atypical Achromatopsia.
• Carrier testing of family members of Achromatopsia patients with known mutations.

For detailed information and ordering instructions, please refer to Full Gene Analysis (1240). Genes may be added or removed from the list below if clinically indicated.

The 2 Achromatopsia-associated genes are listed below:
CNGA3, CNGB3

1. Kohl, et al. Eur J Hum Genet 13, 302-308 (2005).
2. Kohl, et al. Hum Mol Genet 9, 2107-2116 (2000).
3. Wissinger, et al. Am J Hum Genet 69, 722-737 (2001).
4. Kohl, et al. Nat Genet 19, 257-259 (1998).
5. Human Genome Mutation Database: http://www.hgmd.cf.ac.uk/ac/gene.php?gene=CNGA3.