Cognitive, Behavioral, and Adaptive Functioning in Fragile X and Non-Fragile X Retarded Men E
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Sacred Heart University DigitalCommons@SHU Speech-Language Pathology Faculty Publications Speech-Language Pathology 1988 Cognitive, Behavioral, and Adaptive Functioning in Fragile X and Non-Fragile X Retarded Men E. Dykens J. Leckman Rhea Paul Sacred Heart University, [email protected] M. Watson Follow this and additional works at: http://digitalcommons.sacredheart.edu/speech_fac Part of the Communication Sciences and Disorders Commons, Educational Assessment, Evaluation, and Research Commons, and the Special Education and Teaching Commons Recommended Citation Dykens, E., Leckman, J., Paul, R., & Watson, M. (1988). Cognitive, behavioral, and adaptive functioning in fragile X and non-fragile X retarded men. Journal of Autism and Developmental Disorders, 18(1), 41-52. This Article is brought to you for free and open access by the Speech-Language Pathology at DigitalCommons@SHU. It has been accepted for inclusion in Speech-Language Pathology Faculty Publications by an authorized administrator of DigitalCommons@SHU. For more information, please contact [email protected], [email protected]. Journal of Autism and Developmental Disorders, VoL 17, No. 4, 1987 A Comparison of Language Characteristics of Mentally Retarded Adults with Fragile X Syndrome and Those with Nonspecific Mental Retardation and Autism 1 Rhea Paul, 2 Elizabeth Dykens, James F. Leckman, Michael Watson, W. Roy Breg, and Donald J. Cohen Yale Child Study Center and Yale School of Medicine Fragile X syndrome is a recently identified form of mental retardation that is associated with a chromosomal abnormality and inherited in an X-linked manner. Previous studies have suggested that distinctive speech and language characteristics are associated with the syndrome. Twelve adult male residents of an institution for the retarded (aged 23 to 51 years) were compared on a series of speech and language measures to 12 adult males with nonspecific forms of MR who were residents of the same institution and were matched on age and 1Q. A second contrast group consisted of similarly matched au- tistic men. Results revealed that there were no significant differences among the groups'performance, with the exception of increased rates of echolalia in the autistic group. A nonsignificant trend toward poorer performance on expressive measures on the part of the fragile X group was noted. The im- plications of these findings for further research on the syndrome are discussed. 1We wish to express our most sincere appreciation to the staff of the Southbury Training School for their cheerful cooperation throughout this study, most especially to Edward Benjamin, Richard Witham, and Dr. Jean Gino. To our research nurse, Sharon Ort, research associate Wendy Marans, and research assistants Deborah Soriano, Elaine Algiers, and Karen Beebe, whose help in collecting, coding, and rating the data were invaluable, we also express our thanks. This research was supported by grants from the NIMH Mental Health Clinical Research Center grant no MR30929-09, the Children's Clinical Research Center grant no. RR00125-05, NICHD grant no. HPO3008-18, the MacArthur Foundation, the Merck Foundation and U.S. Public Health Service grant no. HD-11624. 2Address all correspondence to Dr. Rhea Paul, Department of Speech, Portland State University, P.O. Box 751, Portland, Oregon 97207. 457 0162-3257/87/1200-0457505.00/0 1987 Plenum Publishing Corporation 458 Paul, Dykens, Leekman, Watson, Breg, and Cohen The fragile X syndrome is a recently identified form of mental retardation (MR) with a characteristic physical and behavioral phenotype that is as- sociated with a chromosomal abnormality and is transmitted within families in an X-linked manner-that is, through generally unaffected female carri- ers to sons who demonstrate the syndrome (Lubs, 1969; see Paul, Cohen, Breg, Watson, & Herman, 1984, for review of history of this syndrome). The condition is diagnosed by observing a pinched area or constriction (fragile site) at the tip of the long arm of some of the X chromosomes in affected males and some female carriers, when cells are grown in media deficient in folic acid or in othe r specialized culture media (Sutherland, 1977). Clinical features of the syndrome include a broad range of intellectual ability varying from profound to borderline levels of functioning (de la Cruz, 1985). A few normal males with themarker have been reported (Daker, Chidi- ac, Fear, & Berry, 1981), and apparent transmission through phenotypically normal males has been documented (Popovich, Vekemans, Rosenblatt, & Monroe, 1982; Webb, Rogers, Pitt, Halliday, & Theobald, 1981). About one- third of the female "carriers" show some degree of impairment, ranging from mild learning disabilities to mental retardation (Turner, Brookwell, Daniel, Selikowitz, & Zilibowitz, 1980). While this form of retardation is not always associated with obvious physical abnormalities, males affected with the fragile X syndrome tend to have abnormally large, low-set ears, slightly enlarged head circumference, long and narrow face with some midface hypoplasia, prominent mandible, and connective tissue dysplasia (de la Cruz, 1985). Tes- ticular enlargement, or macroorchidism, is the most frequent physical ab- normality seen in postpubertal males, although testicular size in young boys may be enlarged but is usually normal (Escalante, Grunspun, & Frota-Pessoa, 1971; Meryash, Cronk, Sachs, & Gerald, 1984). X-linked forms of mental retardation have been found to be quite com- mon. Turner and Turner (1974) estimated that X-linked forms of MR (about half of those with X-linked MR have the fragile X syndrome) could be respon- sible for 20% or more of the moderately retarded male population. Current estimates for the occurrence of the fragile X syndrome of 1 in 2,000 males (Turner & Jacobs, 1983) suggest that this form of MR may be second only to Down's syndrome in prevalence, and it is certainly one of the most com- mon diagnosable forms of mental retardation. Behavioral features include some association with autism (Brown et al., 1982; Meryash, Szymanski, & Gerald, 1982; Levitas et al., 1983; Watson et al., 1984; Blomquist et al., 1985), although estimates of the degree of as- sociation between the two syndromes vary from 5 to 15% in larger series (Watson et al., 1984) to more than 50% in a small series (Levitas et al., 1983). Pervasive hyperactivity has been reported in boys with the syndrome (Hager- man & McBogg, 1983), but this appears to abate in adulthood. Comparison of Language Characteristics 459 One of the first observations of geneticists studying this syndrome was that affected individuals showed peculiar speech characteristics (Allen, Hern- don, & Dudley, 1944; DeRoover, Fryns, Parloir, & VanDenBerghe, 1977; Hagerman & McBogg, 1983; Lehrke, 1974; Martin & Bell, 1943; Ren- penning, Gerrard, Zaleski, & Tabata, 1962; Snyder & Robinson, 1969; Yar- borough & Howard-Peebles, 1976). Language characteristics reported include poor auditory reception (Howard-Peebles, Stoddard, & Mims, 1979), a characteristic rhythmic "litany-like" intonational pattern (Turner et al., 1980), dyspraxic characteristics and dysfluency (Paul et al., 1984), perseverative speech (Herbst, Dunn, Dill, Kalousek, & Krywa- nink, 1981), and high rates of palilalia and echolaIia (Hagerman & McBogg, 1983). While all these characteristics can be found in mentally retarded in- dividuals of any etiology, there has been the strong suggestion in the litera- ture on this syndrome that the constellation of speech disorders seen in affected individuals forms a distinctive pattern. However, none of these studies has systematically compared language characteristics of males with the fragile X syndrome to those of similarly retarded males who do not ex- hibit the marker X chromosome. The present study contrasts language per- formance of males with the fragile X syndrome to that of males with other, nonspecific forms of retardation known not to have the fragile X trait who are matched to the experimental subjects on chronological age, mental age, and institutional status. In addition, the fragile X group's language charac- teristics will be compared to those seen in similarly matched autistic individu- als who do not show the marker X chromosome. METHOD Subjects Fifteen adult males (mean age 38 years) who were long-term residents of a state institution for the retarded were identified as showing the fragile X syndrome. Peripheral blood lymphocytes were cultured in medium 199 with 2% fetal calf serum as previously described (Lubs, Watson, Breg, & Lujan, 1984). Not all residents of the institution were screened for the syn- drome. These men were identified on the basis of family history of mental retardation, testicular enlargement, and/or physical appearance. This was not, then, a complete ascertainment of fragile X syndrome within the insti- tution. Because 3 of the subjects were subsequently placed outside the insti- tution, they were not included in the study. The remaining 12 subjects were able to undergo the complete battery of measures. There were two sibships in the fragile X sample, one of two brothers and one of three. All had nor- 460 Paul, Dykens, Leekman, Watson, Breg, and Cohen mal hearing. Two had been diagnosed as autistic on the basis of behavioral characteristics before they had been identified as having fragile X syndrome. The contrast group consisted of 12 males, all unrelated to each other or to subjects in other diagnostic groups, living in the same institution, who had no