Children at risk for schizophrenia: the Jerusalem Infant Development Study. II. Neurobehavioral deficits at school age

The development of school-age children born to parents with serious mental disorders was assessed on a variety of perceptual-cognitive and motoric tasks. These same children have been followed up from birth as part of the Jerusalem Infant Development Study. Children with schizophrenic parents, when compared with children with healthy parents or parents having other psychiatric disorders, were more likely to show neurobehavioral dysfunctioning in perceptual-cognitive and motoric areas. Forty-four percent of the offspring of schizophrenics (11 of 25 subjects) showed such dysfunctioning. Male subjects were overrepresented in this poorly functioning group. A stable subgroup (40%) of the offspring of schizophrenics (six of 15 subjects) showed dysfunctioning during infancy and school age. None of the offspring of nonschizophrenic parents showed dysfunctioning during both age periods. While most of the poorly functioning children with schizophrenic parents showed perceptual-cognitive and motoric signs, only perceptual-cognitive signs were strongly linked to parental diagnosis and infant dysfunctioning. Motoric signs, but not cognitive signs, were related to pregnancy and birth complications. These findings provide further support to the schizotaxia hypothesis that some neurointegrative deficits may reflect vulnerability to schizophrenia and that these deficits are clearly apparent at school age, long before the onset of illness. However, these signs are not exclusive to schizophrenic illness, although they occur with a greater prevalence in this group. Definitive statements about the validity of early neurobehavioral signs as indicators of genetic vulnerability await further longitudinal follow-up into the age of risk for actual schizophrenic breakdown or when a diagnosis of schizotypal personality disorder may be made.

A prevalence study of autism in tuberous sclerosis

An estimate of the prevalence of autism in tuberous sclerosis (TSC) was made by interviewing the parents of 21 children between ages 3 and 11 ascertained during a previous population study of the condition in the West of Scotland. Five of the children (24%) were rated autistic and a further four (19%), all of whom were girls, had socially impaired behavior categorized as pervasive developmental disorder, without fulfilling all the DSM-III-R criteria for autism. One further boy had disruptive attention-seeking behavior that had excluded him from his normal school. The estimated prevalence from this study of autism in TSC is 1 in 4 children in general, and 1 in 2 of those with mental retardation. Tuberous sclerosis could be a significant cause of autism and pervasive developmental disorders, particularly in girls.

Tourette syndrome and autistic disorder: a significant relationship

The histories of 10 children with autistic disorder or pervasive developmental disorder (PDD) cooccurring with familial Tourette syndrome (TS) are presented. Evidence from the histories of the patients and their relatives combined with other reports of cases of cooccurrence of TS and autism provides support for the hypothesis that TS may be responsible for cases of coocurrence of the disorders, contributes significantly to the etiological heterogeneity of autistic disorder and that a portion of cases of autism may actually be a result of homozygosity for the TS gene. In addition, the presence of affective disorders and autistic-like syndromes or mild disturbances of social relatedness in some of the pedigrees suggests the hypothesis that TS may be responsible for a subgroup of families with cooccurring affective and autistic disorders and for some cases of familial aggregation of autism-PDD.

Clinical and genetic relationships between autism-pervasive developmental disorder and Tourette syndrome: a study of 19 cases

Children with autism or pervasive developmental disorder (PDD) and Tourette syndrome (TS) share a number of symptoms. Forty-one cases have been reported in which PDD patients subsequently developed TS. We term this PDD----TS. We describe an additional 16 such patients plus 3 families where a close relative of a TS proband had autism. There was a high frequency of alcoholism, drug abuse, obsessive-compulsive, and other behavior disorders in the relatives of these patients. This frequency was virtually identical to that observed in relatives of individuals with TS only. We suggest there is an intimate genetic, neuropathologic relatedness between some cases of PDD and TS. Many observations have led us to suggest that the genetic defect in TS may be a mutation of tryptophan oxygenase and that TS is inherited as a semidominant semirecessive trait, i.e., homozygosity for a common gene which shows some expression in the heterozygous state. We propose that some types of PDD are inherited in the same fashion and by the same gene. This would explain the similarity of symptoms, frequent evolution of PDD into TS, the apparent recessive inheritance of PDD despite no increase in consanguinity, the high frequency of behavior problems in the relatives of PDD----TS patients and the serotonin abnormalities.

Pervasive developmental disorder in monozygotic twins

Monozygotic twin brothers were diagnosed as having pervasive developmental disorder, not otherwise specified (DSM-III-R). They show different levels of cognitive and behavioral impairment, consistent with a greater number of suboptimal pre-, peri-, and postnatal factors present in one of the twins. This case study lends support to the hypothesis that genetic factors are of importance in the expression of a pervasive developmental disorder, but that degree of developmental delay, its severity, and certain clinical features may be determined by nongenetic suboptimal pre-, peri-, and postnatal events.

Diagnosis of autism and other pervasive developmental disorders

Problems in the diagnosis of autism and other pervasive developmental disorders are reviewed. Modification and application of recent developments in neuroimaging, molecular genetics and population studies are presented. A prioritized list of needed investigations is discussed.

Familial pervasive development disorder, Tourette disorder and hyperlexia

Four children and one adult have been found to have Pervasive Developmental Disorder, Tourette disorder and hyperlexia in North Dakota, a state with a population of 204,161 children ages 0-18. Assuming that these are independent disorders the probability of these three disorders occurring by chance in one child is 3.39 x 10(-12). Two of these individuals are from the same family. This suggests evidence for genetic linkage among these three disorders.

Psychiatric disability in female carriers of the fragile X chromosome

Fragile X syndrome, an X-linked genetic condition, is an important genetic cause of mental retardation in males. In addition to mental retardation, hemizygous males with fragile X syndrome appear to have a greater likelihood of displaying behaviors classified under the diagnostic category of pervasive developmental disorder than would be expected on the basis of mental retardation alone. Although the majority of female heterozygotes with the fragile X genetic defect are of normal intelligence, our clinical work with this population and a recent case report have suggested that females with fragile X syndrome have an increased rate of schizophrenia spectrum and affective disorders. In this study, the relationship of the fragile X genetic defect to psychopathology in female heterozygotes is investigated by psychiatric evaluation of 35 obligate female carriers of the fragile X chromosome and a comparison group of 24 fragile X-negative controls. Female fragile X carriers were found to have a greater frequency of psychopathology associated with schizophrenia spectrum diagnoses, particularly schizotypal features. A weaker association between the fragile X genetic defect and chronic affective disorders was detected. The specificity of the neuropsychiatric phenotype occurring in particular genetic conditions such as the fragile X syndrome adds a potentially valuable tool to the study of psychopathology in the general population.

A family with fragile-X syndrome

A family with fragile-X syndrome is reported. One sibling has atypical pervasive developmental disorder and moderate mental retardation. A second sibling has Tourette's syndrome, moderate mental retardation, seizure disorder, and autism. A third sibling has attention deficit disorder, moderate mental retardation, and developmental language disorder, expressive type. The authors believe that this family represents a classic example of the differential outcome of interactions of common biogenetic and environmental influences. We propose that in this family the multipotential outcome is at least influenced by if not caused by a common genetic defect.

Neurobiologic antecedents of schizophrenia in children. Evidence for an inherited, congenital neurointegrative defect

In chronic schizophrenics, disordered motor development in childhood is followed by more early cognitive and social impairment and poorer outcome; childhood schizophrenics represent the most extreme variants of this. Preschizophrenic infants show a fluctuating dysregulation of maturation--or "pandevelopmental retardation" (PDR)--that involves physical growth; gross motor, visual-motor, and cognitive development; proprioceptive and vestibular responses; muscle tone; and possibly arousal. Pandevelopmental retardation was significantly related to a genetic history for schizophrenia (less than .05), but not to obstetric complications. The severity of PDR was significantly related to the severity of later psychiatric and cognitive disorder (less than .01). Pandevelopmental retardation provides a "marker" in infancy for the inherited neurointegrative defect in schizophrenia. These disordered functions should be studied by anyone interested in the biology of the schizophrenic genotype or in specific early interventions for children at risk.