Prevalence of mental retardation in patients with hereditary retinoblastoma

Abstract

Dear Editor, We evaluated the cumulative incidence of mental retardation in patients with hereditary retinoblastoma. Records of the national Dutch retinoblastoma register were used. This register is complete from 1945 through 1994. Cooperation of the hereditary retinoblastoma patients or their parents was solicited by a letter from the ophthalmologist. The patients with hereditary retinoblastoma born between 1945 and 1970 were visited at home in 1985.' On that occasion, information on mental retardation was collected. In addition, questionnaires were sent in 1993 to the patients' parents or caregivers to obtain up-to-date information regarding the patient's condition, visual acuity, and second primary tumors. Parents of the hereditary retinoblastoma patients born between 1971 and 1994 were visited at home.2 Information was obtained on the possible causes of the mental retardation: brain damage or fetal, perinatal, or postnatal disorders (infection, trauma, medication, or anoxia). The reported disorders were verified and the data regarding karyotyping and D N A analyses, if available, were traced by a letter to the general physician. Information regarding the visual acuity, if available, was obtained from the ophthalmic surgeon. Since the measurement of the intelligence quotient of mentally and visually handicapped persons is complicated and not often valid,' this parameter cannot be used to define mentally handicapped retinoblastoma patients. Therefore, the following criteria for mental retardation were used: the necessity of residential treatment for mental retardation or home care with day treatment and special education. These criteria only define severely and modcrately

Required Reduction in Dose of Chemotherapy for Retinoblastoma Due to Down Syndrome-Associated Chemosensitivity

“…[1][2][3] These reports, in combination with large epidemiologic studies performed in Norway and Denmark, suggest an association between RB and Down syndrome. There have also been several studies demonstrating that children with Down syndrome experience more side effects from chemotherapy than children without Down syndrome.…”

A survey of ocular tumors in Down syndrome alone or associated with another genetic affection

“…First, Windham et al (25) in an epidemiologic study on cancer linked to twining and to congenital malformations or low birth weight in Norway found a "higher rate of retinoblastoma based on only one case" for children with DS. Third, Moll et al (30,31) found two patients with DS in the Dutch Retinoblastoma Register among 241 cases of hereditary retinoblastoma and concluded that "hereditary retinoblastoma patients may have an increased risk for Down syndrome". Third, Moll et al (30,31) found two patients with DS in the Dutch Retinoblastoma Register among 241 cases of hereditary retinoblastoma and concluded that "hereditary retinoblastoma patients may have an increased risk for Down syndrome".…”