title: Xq28: epidemiology and sex-linkage between red-green colour blindness and G6PD deficiency.
abstract: Xq28 is the genetic locus of two closely associated conditions of red-green colour blindness and G6PD deficiency. Epidemiologically, both rank among the more frequent sex-linked clinical problems that affect military servicemen in Singapore. This retrospective study is based on the findings of 35714 subjects screened at the Medical Classification Centre--Central Manpower Base (MCC--CMPB) over an eighteen-month period using pseudoisochromatic and fluorescent techniques as well as anomaloscopic and spectrometric methods. The overall prevalence rates of red-green colour blindness, G6PD deficiency and association were determined to be 4.8%, 2.2% and 0.1% respectively. Malays showed the highest prevalence rates among the major races. Statistically significant difference was found with regards to the prevalence rates of G6PD deficiency and its association with red-green colour blindness. Review of literature yielded comparable results with a few local studies of good sample size done over the past twenty years. Sex-linkage analysis was hindered by the lack of pedigree studies.
authors.affiliation: Medical Classification Centre, Central Manpower Base, Ministry of Defence, Singapore.
authors.forename: Y K
authors.initials: YK
authors.lastname: Chan
authors.forename: M T
authors.initials: MT
authors.lastname: Tay
authors.forename: M K
authors.initials: MK
authors.lastname: Lim
mesh_terms: D000293:Adolescent; D000328:Adult; D003117:Color Vision Defects / Q000145:classification / Q000453:epidemiology / Q000235:genetics*; D005006:Ethnicity; D008040:Genetic Linkage; D005955:Glucosephosphate Dehydrogenase Deficiency / Q000235:genetics*; D006801:Humans; D008297:Male; D015995:Prevalence; D012189:Retrospective Studies; D012846:Singapore / Q000453:epidemiology; D014960:X Chromosome