Infantile autism: An occasional manifestation of fragile (X) mental retardation

Abstract

Classical infantile autism occurs more frequently in males and has recently been noted in patients with the fragile (X) form of X-linked mental retardation (XLMR). In order to better understand this association and to determine whether fra(X) XLMR could account for the excess of autistic males, we investigated a group of institutionalized severely handicapped adults, 33 males and eight females, who were diagnosed as autistic using the DSM III diagnostic criteria of infantile autism. Chromosome studies using FUdR showed that three of the males had the Xq27 fragile site. We confirmed the association of autism and fra(X) XLMR, and showed that this extreme form of behaviour is part of the spectrum seen in the Martin-Bell syndrome. Two of the three autistic males with the Xq27 fragile site had a history of birth insults, which in combination with developmental deficits due to the fragile X gene, might have led to the behavioural disorder. Even though the fragile X cannot account for the excess of males with classical autism, it is an important X-linked factor in its cause. The diagnosis can allow more accurate counselling for this subset of autistic males.

Serotonin Metabolism and Other Biochemical Parameters in Infantile Autism

“…4). This might (1) correspond to subgroups of the population labelled 'autistic' such as patients with adenylosuccinate lyase deficiency autism [96] and more generally purine autism [97] which might be related to immunological deficiencies [98] affecting autistic children [40][41][42][43][44] and (2) suggest a link between autism and folate metabolism which interacts with bioamine metabolism [99,100], particularly at the hydroxylase levels [101] -distur bances of which have been reported in various types of psychoses [102], Folic acid has also been proposed as an adjunct in the treatment of children with the autism-fragile X syn drome [103], the occurrence of which depends on the study considered [104][105][106][107][108][109]. Anyhow, the formation of P-carbolines, for instance, might, therefore, be investi gated in autism.…”

Dermatoglyphic analysis of autistic Basque children

“…AutisticINTRODUCTION "Infantile autism probably has many causes" [Folstein, 19851, as might be expected in a syndrome defined only by its clinical manifestations. Children with autism of known or presumed cause constitute only a small proportion of all autistic children; those with known infectious or genetic causes are not ordinarily included in most cases series [Deykin and McMahon, 1979;Brown et al, 1982;Meryash et al, 1982;Markowitz, 1983;McGillivray et al, 1984;Watson et al, 1984;Tariverdian et al, 19871. Due to the close relationship between ridge differentiation and limb embryogenesis, many early developmental disorders are reflected in the ridges. As far as we know, only four previous investigations have been published on dermatoglyphics and autism [Walker, 1976;Riviere et al, 1978;Sank and Firschein, 1979;Arrieta et al, 19881.…”

Autism in Fragile X Syndrome; A Functional MRI Study of Facial Emotion-Processing

“…It was recognized in some of the early described series of confirmed individuals with fragile X syndrome that there were higher levels of autistic traits, by way of social, communication, and sensory difficulties; than could be accounted for by level of intellectual disability alone [2][3][4][5][6][7]. In parallel, early studies in which groups with autism were screened for fragile X reported that up to 16% of autistic males had fragile X syndrome [8][9][10][11][12][13]. With autism now being more widely recognized, especially in those without an intellectual disability, these estimates are consequently lower, with fragile X syndrome accounting for approximately 0.5% of individuals with autism [14][15][16].…”