ABSTRACT
We report a neurological disease among Cree Indian children in a northern Quebec village. The disease manifests as severe mental retardation, cerebral atrophy with white matter changes and calcifications, and systemic immunological abnormalities. Eleven cases are known in five families. The familial incidence of cases and the high degree of parental consanguinity suggest a genetic contribution. We propose that this entity may be caused by an unusual viral infection in a genetically vulnerable host.
Subject(s)
Brain Diseases/etiology , Calcinosis/etiology , Encephalitis/epidemiology , Intellectual Disability/etiology , Adolescent , Antibodies, Viral/blood , Atrophy , Brain Diseases/genetics , Brain Diseases/microbiology , Calcinosis/genetics , Calcinosis/microbiology , Child , Child, Preschool , Encephalitis/complications , Encephalitis/genetics , Female , Humans , Infant , Infant, Newborn , Intellectual Disability/genetics , Intellectual Disability/microbiology , Male , QuebecABSTRACT
We report 14 cases of a severe familial leukoencephalopathy among native North American Indian infants in northern Quebec and Manitoba. Affected infants have hypotonia and mild motor delay, followed by seizures, hypotonia or spasticity, eye deviation, and abnormal posture during a febrile illness around 6 months of age. Death follows a rigid, vegetative state that manifests days to months after disease onset and is marked in some cases by prominent autonomic disturbances, blindness, and cessation of head growth. Symmetrical hemispheric white matter lucencies and diffuse hypomyelination of the cerebral hemispheres and brainstem are the radiological and pathological hallmarks. This disease differs from the known diseases of cerebral myelin. An autosomal recessive pattern of inheritance awaits statistical confirmation. The proposed cause is a delay in development or abnormal turnover of central nervous system myelin.
Subject(s)
Leukoencephalopathy, Progressive Multifocal/epidemiology , Brain/ultrastructure , Female , Humans , Infant , Leukoencephalopathy, Progressive Multifocal/genetics , Male , Manitoba , Microscopy, Electron , Muscle Hypotonia/etiology , Myelin Sheath/ultrastructure , QuebecSubject(s)
Rotifera/drug effects , Vitamin E/analysis , Animals , Biological Assay , Vitamin E/pharmacologyABSTRACT
Sexuality and polymorphism are closely coupled in the rotifer Asplanchna sieboldi. In a graded response to dietary tocopherol, embryos develop body-wall outgrowths of various sizes and shapes. Also in a graded response to this compound, some of the affected females produce eggs undergoing meiotic instead of mitotic oogenesis. The haploid eggs of such mictic females develop parthenogenetically into males instead of females. The incidence of mictic females among animals with different shapes was studied among cohorts from mothers subjected to different inducing conditions. The hypothesis that external tocopherol concentrations absolutely fix the probability of meiotic oogenesis was rejected. The other extreme hypothesis, that the probability of meiotic oogenesis is fixed by morphotype, was rejected for animals at the low end of the morphotypic scale but accepted for the more strongly-affected individuals. The probability of meiotic oogenesis is thus constant for the higher morphotypes. The ascertainment of morphotype frequencies in natural or laboratory populations may suffice for estimating the incidence of sexual forms; furthermore studies of factors affecting the body-wall-outgrowth response may also bear directly upon regulation of sexual reproduction in this species.
