Prevalence of tapeto-retinal dystrophies among Danish children

Abstract

Age specific prevalence rates are presented based on 110 cases of pigmentary retinopathy (RP) recorded in the Danish child population of a little over one million individuals on January 1, 1988. A steady and steep rise in age specific prevalences of notified RP throughout infancy and childhood was found. The material consisted in 52 non-systemic and 58 systemic cases. 35 of the systemic cases could be nosologically identified, leaving 23 cases unidentified with respect to known diseases or syndromes. Among the genetic types autosomal recessive inheritance was the most common with 60 cases (55%). Parental consanguinity was less frequent than hitherto reported. On the other hand undetected carrier state for X-linked tapeto-retinal dystrophy played a more significant role than expected. A clear excess of males among the simplex cases indicated that some X-linked cases may still be unrecognized. A significant proportion of non-systemic, early infantile RP with an autosomal recessive or simplex mode of inheritance are clinically and electrophysiologically characterised as cone-rod dystrophies.

The epidemiology of retinitis pigmentosa in Denmark

“…He registered 400 cases and analysed them according to heredity. Epidemiological RP‐research concerning children has been resumed in the last two decades and was based on the Register for the Visually Impaired Children (Rosenberg 1987, 1989) and later by the Nordsyn study group (Hansen et al. 1992).…”

Prevalence of retinitis pigmentosa and allied disorders in Denmark

“…Our definition included any case of tapetoretinal dystrophy (RP) with congenital nystagmus (RP has been defined previously by Haim et al (1992)). This definition was chosen due to diEculties in establishing whether the retinal dystrophy was present at birth or presented later in childhood (Rosenberg 1989). Still, the definition has its shortcomings e.g.…”

A population survey of retinitis pigmentosa and allied disorders in Denmark

“…Blind students have been registered here since 1858, and medical files have been kept here since 1892. In the 1920's a registration of out-patients and partially sighted persons was initiated, and after World War I1 the registration of visually handicapped children was extended to patients treated elsewhere in the country (Rosenberg 1989). A diagnostic index exists for all files since September 1, 1922.…”