13q32.1 as a candidate region for physiological anisocoria

Abstract

BackgroundPhysiological anisocoria is an asymmetry of pupil size in the absence of pathology.MethodsImages of the pupils under standard illumination were collected in the course of a whole-genome association study of a range of visual functions in 1060 healthy adults. DNA for each participant was extracted from saliva samples.ResultsWe found no relationship between anisocoria and the difference in refraction between the eyes, nor between anisocoria and difference in acuity. There was a small but significant relationship with lightness of the iris, in that the eye with the smaller pupil was associated with the lighter iris. There was a strong association between anisocoria and a local region of chromosome 13 (13q32.1), a region lying between the genes GPR180 and SOX21. The strongest association was with the single-nucleotide polymorphism rs9524583.ConclusionThe very specific region associated with anisocoria is one where microdeletions (or microduplications) are known to lead to abnormal development of pupil dilator muscle and hence to the autosomal dominant condition of microcoria. It is possible that alterations at 13q32.1 act by altering the expression of SOX21, which encodes a nuclear transcription factor.

Evidence for an Association Between a pH-Dependent Potassium Channel, TWIK-1, and the Accuracy of Smooth Pursuit Eye Movements

“…Oculomotor measures were recorded as part of the PERGENIC project, in which we tested a population of 1058 young adults (413 male) on a 2.5-hour battery of optometric, perceptual and oculomotor tests. 33 – 35 Participants were recruited from the Cambridge area by advertisements within the University and online, and a large proportion were students at the University of Cambridge. Their age range was 16–40, with a mean age of 22.14 (standard deviation [SD] = 4.09).…”