We have studied the prevalence of the fra (X) and of the autosomal fragile sites fra (10) (q25) and fra (16) (q22) in patients from an institute for the mentally retarded in Italy. We found six cases (1.9%) of fra (10) (q25) and 9 (2.9%) of fra (16) (q22). The study of the fra (X) was restricted to a subgroup of 91 males who did not have other chromosome anomalies or variants, and led to the discovery of 4 fra (X) cases. These 4 had the Martin-Bell syndrome; 3 of them were epileptic and had a characteristic EEG pattern originating during sleep from the temporal lobe not previously described in fra (X) mental retardation.

Adolescent↗

PubMedDate not supplied

Prevalence of a novel epileptogenic EEG pattern in the Martin-Bell syndrome.

In this paper, we describe a study aiming at establishing the prevalence, specificity, and the sensitivity of a characteristic sleep EEG pattern in patients with Martin-Bell syndrome, in comparison with a sample of etiologically different mentally retarded patients. The estimation of the prevalence (11% among the total sample), the specificity, and the sensitivity, allows us to propose this pattern as an important "marker", useful in the diagnosis of the Martin-Bell syndrome.

Adolescent↗

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Simpson-Golabi-Behmel syndrome: an X-linked encephalo-tropho-schisis syndrome.

We report on another family with the so-called "gigantism-dysplasia syndrome", an X-linked condition characterized by pre- and postnatal overgrowth, characteristic face with apparent coarseness, dysplastic changes in several tissues, and mild intellectual impairment. This condition has been called the Golabi-Rosen syndrome; however, we agree that is the same entity as that described, in a milder form, by Simpson et al in 1975 and by Behmel et al in 1984. Therefore, we suggest that this entity be designated the Simpson-Golabi-Behmel syndrome. The manifestations in affected individuals suggest that this condition represents an X-linked encephalo-tropho-schisis syndrome.

Abnormalities, Multiple↗

PubMedDate not supplied

Fragile X expression in normal and mentally retarded subjects: effect of treatment with an antifolic agent.

Expression of the fragile site fra(X) (q27.3) in peripheral lymphocytes was evaluated in mentally retarded patients and in normal control individuals before and after administration of the antifolic agent trimethoprim for 7 days. This treatment was effective in converting the status of some individuals from fra(X)-negative to fra(X)-positive. However, the induced level of fra(X) expression was very low and not significantly different in patients and in control subjects and did not increase in those individuals where it was already present before treatment. These data support the contention that fra(X)(q27.3) is a common fragile site and that treatment in vivo with an antifolic agent is not effective in enhancing its degree of expression in vitro. Therefore, such treatment seems to be of no diagnostic value in those cases where the fra(X) syndrome is suspected clinically, but where there is no or very low cytogenetic expression of the fra(X).

Adolescent↗

PubMedDate not supplied

The fragile X in Sicily: an epidemiological survey.

We have studied a group of 349 institutionalized propositi with mental retardation, and found 12 fra(X)-positive cases among 155 males (7.7%) and 8 fra(X)-positive cases among 194 females (4.1%). The males had characteristic manifestations of the Martin-Bell syndrome. Another 7 males, who were initially considered "borderline", having expression of fra(X) less than 4% and a non-characteristic phenotype, were eventually considered negative. Among 5,624 patients (2,764 males and 2,860 females) that were admitted to the Pediatric Department of the University of Catania during the period July 1986 - June 1987, 210 (120 males and 90 females) had mental retardation. Of these, 75 were analyzed for the presence of fra(X) (q27.3); 5 males (0.18% of all males) and 2 females (0.07% of all females) were fra(X)-positive. The males had the Martin Bell syndrome phenotype. The presence of fra(X) (q27) was confirmed in another 4 male propositi that were referred to our outpatient services with a clinical diagnosis of Martin-Bell syndrome.

Adolescent↗

PubMedDate not supplied

Conference report: Fourth International Workshop on the fragile X and X-linked mental retardation.

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Female↗

PubMedDate not supplied

XLMR genes: update 1990.

We have identified 39 X-linked conditions in which mental retardation seems to be the primary characteristic, although pathogenesis is unknown. These conditions can be subdivided into syndromal and non-syndromal, depending on the existence of a recognizable pattern of minor anomalies and/or malformations, or lack thereof. Seventeen genes have been regionally mapped onto the X chromosome. However, in 14 instances the data were derived from a single family and most lod scores were less than 3.0.

Chromosome Mapping↗