Molecular genetics of achromatopsia
Reviewed by Nana Theodorou

Achromatopsia is a rare autosomal recessive disorder of the cone photoreceptors. Typical characteristics of affected patients include the inability to distinguish colours, impaired visual acuity, photophobia and nystagmus. The condition is said to be more frequent in the Pingelapese population of the Pacific islands. This study included 16 patients from Newfoundland, Canada who were sequenced for mutations in four known achromatopsia genes (CNGA3, CNGB3, GNAT2, and PDE6C). Twelve of the patients were found to be either homozygotes or compound heterozygotes for known achromatopsia alleles, two in CNGB3 (p.T383fsX and p.T296YfsX9) and three in CNGA3 (p.R283Q, p.R427C and p.L527R). Haplotype reconstruction showed that recurrent mutations p.T383fsX and p.L527R were due to a founder effect. Aggregate data from exome sequencing, segregation analysis and archived medical records supported a diagnosis of Jalili syndrome in four affected siblings from one of the participating families. According to the authors this was the first family identified with Jalili Syndrome in North America.

Molecular genetics of achromatopsia in Newfoundland reveal genetic heterogeneity, founder effects and the first cases of Jalili syndrome in north America.
Doucette L, Green J, Black C, et al.
OPHTHALMIC GENETICS
2013;34(3):119-29.