title: Multicenter genetic study of retinitis pigmentosa in Japan: II. Prevalence of autosomal recessive retinitis pigmentosa.
abstract: Retinitis pigmentosa (RP) is a group of genetically heterogeneous diseases with autosomal recessive (AR), autosomal dominant, and X-linked modes of inheritance. Autosomal recessive retinitis pigmentosa (ARRP) is the most common form in Japan. A genetic analysis was done to determine the prevalence of ARRP indirectly, to provide an estimation of changing trends in the overall prevalence of RP. Data on the frequency of consanguinity and marriage year of normal parents of 59 ARRP patients were obtained from a nationwide multicenter survey of typical retinitis pigmentosa conducted in 1990. The gene frequency of ARRP was 0.01145 (Dahlberg's formula). In 1990, the number of young symptomatic ARRP patients decreased, while the number of patients aged 40 years and older increased. The total number of symptomatic ARRP patients in 1990 was nearly 21% higher than in 1970. Despite a dramatic decline in consanguinity in recent decades in Japan, the number of ARRP patients has increased. This increase is attributed to greater longevity and overall population growth. Our results suggest that the total number of RP patients has not decreased, and may even have increased.
authors.affiliation: Department of Ophthalmology, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Hayakawa
authors.forename: K
authors.initials: K
authors.lastname: Fujiki
authors.forename: A
authors.initials: A
authors.lastname: Kanai
authors.forename: M
authors.initials: M
authors.lastname: Matsumura
authors.forename: Y
authors.initials: Y
authors.lastname: Honda
authors.forename: H
authors.initials: H
authors.lastname: Sakaue
authors.forename: M
authors.initials: M
authors.lastname: Tamai
authors.forename: T
authors.initials: T
authors.lastname: Sakuma
authors.forename: T
authors.initials: T
authors.lastname: Tokoro
authors.forename: T
authors.initials: T
authors.lastname: Yura
authors.forename: N
authors.initials: N
authors.lastname: Kubota
authors.forename: S
authors.initials: S
authors.lastname: Kawano
authors.forename: M
authors.initials: M
authors.lastname: Matsui
authors.forename: M
authors.initials: M
authors.lastname: Yuzawa
authors.forename: Y
authors.initials: Y
authors.lastname: Oguchi
authors.forename: K
authors.initials: K
authors.lastname: Akeo
authors.forename: E
authors.initials: E
authors.lastname: Adachi
authors.forename: T
authors.initials: T
authors.lastname: Kimura
authors.forename: Y
authors.initials: Y
authors.lastname: Miyake
authors.forename: M
authors.initials: M
authors.lastname: Horiguchi
authors.forename: K
authors.initials: K
authors.lastname: Wakabayashi
authors.forename: N
authors.initials: N
authors.lastname: Ishizaka
authors.forename: K
authors.initials: K
authors.lastname: Koizumi
authors.forename: M
authors.initials: M
authors.lastname: Uyama
authors.forename: N
authors.initials: N
authors.lastname: Ohba
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D002648:Child; D003241:Consanguinity; D005260:Female; D005787:Gene Frequency / Q000235:genetics*; D005808:Genes, Recessive / Q000235:genetics*; D006720:Homozygote; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008393:Marriage; D008875:Middle Aged; D011159:Population Surveillance; D015995:Prevalence; D012174:Retinitis Pigmentosa / Q000453:epidemiology* / Q000235:genetics*; D012189:Retrospective Studies