Hostname: page-component-745bb68f8f-l4dxg Total loading time: 0 Render date: 2025-02-08T17:33:27.648Z Has data issue: false hasContentIssue false
  • English
  • Français

The Fragile-X Syndrome

On the Way to a Behavioural Phenotype

Published online by Cambridge University Press:  02 January 2018

Jeremy Turk
Jeremy Turk*
Affiliation:
Academic Department of Child Psychiatry, Institute of Child Health, 30 Guilford Street, London WC1N 1EH
Get access Rights & Permissions [Opens in a new window]

Abstract

The fragile-X syndrome accounts for up to 10% of individuals with mental handicap, and 50% of cases of X-linked mental retardation. Knowledge of the genetic basis of mental functioning, psychopathology, and neuropsychology is being furthered by this recently recognised condition. The disorder has considerable significance for psychiatrists, particularly, but by no means exclusively, those working in the field of mental handicap and with children. This review outlines the slow clarification of this complex and important behavioural phenotype and the implications of these advances for identification, diagnosis, genetic counselling and a wide range of management interventions.

Type
Review Articles
Information
The British Journal of Psychiatry , Volume 160 , Issue 1 , January 1992 , pp. 24 - 35
Copyright
Copyright © The Royal College of Psychiatrists 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

August, G. J. & Lockhart, L. H. (1984) Familial autism and the fragile-X chromosome. Journal of Autism and Developmental Disorders, 14, 197–204.Google Scholar
Arinami, T., Sato, M., Nakajima, S., et al (1988) Auditory brainstem responses in the fragile X syndrome. American Journal of Human Genetics, 43, 46–51.Google Scholar
Blomquist, H. K., Gustavson, K. H., Holmgren, G., et al (1982) Fragile site X chromosomes and X-linked mental retardation in severely retarded boys in a northern Swedish county. A prevalence study. Clinical Genetics, 21, 209–214.Google Scholar
Blomquist, H. K., Gustavson, K. H., Holmgren, G., et al (1983) Fragile X syndrome in mildly mentally retarded children in a northern Swedish county. A prevalence study. Clinical Genetics, 24, 393–398.CrossRefGoogle Scholar
Blomquist, H. K., Bohman, M., Edvinsson, S. O., et al (1985) Frequency of the fragile X syndrome in infantile autism. Clinical Genetics, 27, 113–117.CrossRefGoogle ScholarPubMed
Borghgraef, M., Fryns, J. P., Dielkens, A., et al (1987) Fragile (X) syndrome: a study of the psychological profile in 23 prepubertal patients. Clinical Genetics, 32, 179–186.Google Scholar
Bregman, J. D., Dykens, E., Watson, M., et al (1987) Fragile X syndrome: variability of phenotypic expression. Journal of the American Academy of Child and Adolescent Psychiatry, 26, 463–471.Google Scholar
Bregman, J. D., Leckman, J. F. & Ort, S. I. (1988) Fragile X syndrome: genetic predisposition to psychopathology. Journal of Autism and Developmental Disorders, 18, 343–354.Google Scholar
Brondum Nielsen, K. (1983) Diagnosis of the fragile X syndrome (Martin-Bell syndrome). Clinical findings in 27 males with the fragile site at Xq28. Journal of Mental Deficiency Research, 27, 211–226.Google Scholar
Brondum Nielsen, K., Tommerup, N., Dyggve, H. V., et al (1982) Macroorchidism and fragile X in mentally retarded males. Human Genetics, 61, 113–117.CrossRefGoogle Scholar
Brown, W. T., Friedman, E., Jenkins, E. C., et al (1982a) Association of fragile X syndrome with autism. Lancet, i, 100.Google Scholar
Brown, W. T., Jenkins, E. C., Friedman, E., et al (1982b) Autism is associated with the fragile-X syndrome. Journal of Autism and Developmental Disorders, 12, 303–308.Google Scholar
Brown, W. T., Jenkins, E. C., Cohen, I. L., et al (1986) Fragile-X and autism: a multicenter survey. American Journal of Medical Genetics, 23, 341–352.CrossRefGoogle ScholarPubMed
Bundey, S., Webb, T. P., Thake, A., et al (1985) A community study of severe mental retardation in the West Midlands and the importance of the fragile X chromosome in its aetiology. Journal of Medical Genetics, 22, 258–266.Google Scholar
Carpenter, N. J., Leichtman, L. G. & Say, B. (1982) Fragile X-linked mental retardation. American Journal of Diseases of Children, 136, 392–398.Google Scholar
Chudley, A. (1984) Behavior phenotype. In Conference Report: International Workshop on the Fragile X Syndrome and X-linked Mental Retardation (eds Chudley, A. & Sutherland, G.). American Journal of Medical Genetics, 17, 45–53.Google Scholar
Chudley, A. & Hagerman, R. J. (1987) Fragile X syndrome. Journal of Pediatrics, 110, 821–831.Google Scholar
Chudley, A. T., Knoll, J., Gerrard, J. W., et al (1983) Fragile (X) X-linked mental retardation 1: Relationship between age and intelligence and the frequency of expression of fragile (X) (q28). American Journal of Medical Genetics, 14, 699–712.Google Scholar
Cohen, I. L., Fisch, G. S., Sudhalter, V., et al (1988) Social gaze, social avoidance, and repetitive behavior in fragile X males: a controlled study. American Journal of Mental Retardation, 92, 436–446.Google Scholar
Cohen, I. L., Brown, W. T., Jenkins, E. C., et al (1989a) Fragile X syndrome in females with autism. American Journal of Medical Genetics, 34, 302–303.Google Scholar
Cohen, I. L., Vietze, P. M., Sudhalter, V., et al (1989b) Parent-child dyadic gaze patterns in fragile X males and in non-fragile X males with autistic disorder. Journal of Child Psychology and Psychiatry, 30, 845–856.Google Scholar
Cole, T. R. P. & Hughes, H. E. (1990) Sotos syndrome. Journal of Medical Genetics, 27, 571–576.CrossRefGoogle ScholarPubMed
Conners, C. K. (1973) Rating scales for use in drug studies with children. Psychopharmacology Bulletin (Special Issue, Pharmacotherapy of Children), 24–84.Google Scholar
Courchesne, E., Yeung-Courchesne, R., Press, G. A., et al (1988) Hypoplasia of cerebellar vermal lobules VI and VII in autism. New England Journal of Medicine, 318, 1349–1354.Google Scholar
Crowe, S. F. & Hay, D. A. (1990) Neuropsychological dimensions of the fragile X syndrome: support for a non-dominant hemisphere dysfunction hypothesis. Neuropsychologia, 28, 9–16.Google Scholar
Curfs, L. M. G., Borghgraef, M., Wiegers, A., et al (1989a) Strengths and weaknesses in the cognitive profile of Fra(X) patients. Clinical Genetics, 36, 405–410.Google ScholarPubMed
Curfs, L. M. G., Schreppers-Tijdink, G., Wiegers, A., et al (1989b) Intelligence and cognitive profile in the fra(X) syndrome: a longitudinal study in 18 fra(X) boys. Journal of Medical Genetics, 26, 443–446.Google Scholar
Davies, K. E. (1989) The Fragile X Syndrome. Oxford: Oxford University Press.Google Scholar
Dykens, E., Leckman, J., Paul, R., et al (1988) Cognitive, behavioral, and adaptive functioning in fragile X and non-fragile X retarded men. Journal of Autism and Developmental Disorders, 18, 41–52.CrossRefGoogle ScholarPubMed
Dykens, E., Hodapp, R. M., Ort, S., et al (1989) The trajectory of cognitive development in males with fragile X syndrome. Journal of the American Academy of Child and Adolescent Psychiatry, 28, 422–426.Google Scholar
Einfeld, S., Molony, H. & Hall, W. (1989) Autism is not associated with the fragile X syndrome. American Journal of Medical Genetics, 34, 187–193.Google Scholar
Ferri, R. (1989) Brain-stem auditory evoked poten-tials in the fragile X syndrome. American Journal of Human Genetics, 45, 977–978.Google Scholar
Finelli, P. F., Pueschel, S. M., Padre-Mendoza, T., et al (1985) Neurological findings in patients with the fragile-X syndrome. Journal of Neurology, Neurosurgery and Psychiatry, 48, 150–153.Google Scholar
Fisch, G. S., Cohen, I. L., Wolf, E. G., et al (1986) Autism and the fragile X syndrome. American Journal of Psychiatry, 143, 71–73.Google ScholarPubMed
Fisch, G. S., Cohen, I. L., Jenkins, E. C., et al (1988a) Screening developmentally disabled male populations for fragile X: the effect of sample size. American Journal of Medical Genetics, 30, 655–663.Google Scholar
Fisch, G. S., Cohen, I. L., Gross, A. C., et al (1988b) Folic acid treatment of fragile X males: a further study. American Journal of Medical Genetics, 30, 393–399.Google Scholar
Fryns, J. P. (1986) The female and the fragile X. A study of 144 obligate female carriers. American Journal of Medical Genetics, 23, 157–169.Google Scholar
Fryns, J. P. & van den Berghe, H. (1983) X-linked mental retardation and fragile (Xq27) site. Clinical Genetics, 23, 203–206.Google Scholar
Fryns, J. P., Jacobs, J., Kleczkowska, A., et al (1984) The psychological profile of the fragile X syndrome. Clinical Genetics, 25, 131–134.Google Scholar
Gardner, R. J. M. & Sutherland, G. R. (1989) The fragile X syndrome. In Chromosome Abnormalities and Genetic Counselling. Oxford: Oxford University Press.Google Scholar
Gillberg, C. (1983) Identical triplets with infantile autism and the fragile X syndrome. British Journal of Psychiatry, 143, 256–260.Google Scholar
Gillberg, C. & Wahlstrom, J. (1985) Chromosome abnormalities in infantile autism and other childhood psychoses: a population study of 66 cases. Developmental Medicine and Child Neurology, 27, 293–304.Google Scholar
Gillberg, C., Persson, E. & Wahlstrom, J. (1986) The autism-fragile-X syndrome (AFRAX): a population-based study of ten boys. Journal of Mental Deficiency Research, 30, 27–39.Google Scholar
Gillberg, C., Ohlson, V. A., Wahlstrom, J., et al (1988) Monozygotic female twins with autism and the fragile-X syndrome (AFRAX). Journal of Child Psychology and Psychiatry, 29, 447–451.Google Scholar
Goldfine, P. E., McPherson, P. M., Heath, A., et al (1985) Association of fragile X syndrome with autism. American Journal of Psychiatry, 142, 108–110.Google ScholarPubMed
Goldfine, P. E., McPherson, P. M., Hardesty, V. A., et al (1987) Fragile-X chromosome associated with primary learning disability. Journal of the American Academy of Child and Adolescent Psychiatry, 26, 589–592.CrossRefGoogle ScholarPubMed
Grigsby, J. P., Kemper, M. B. & Hagerman, R. J. (1987) Developmental Gerstmann syndrome without aphasia in fragile X syndrome. Neuropsychologia, 25, 881–891.Google Scholar
Grigsby, J. P., Kemper, M. B. & Hagerman, R. J. et al (1990) Neuropsychological dysfunction among affected heterozygous fragile X females. American Journal of Medical Genetics, 35, 28–35.Google Scholar
Hagerman, R. J. (1987) Fragile X syndrome. Current Problems in Pediatrics, 17, 627–674.Google Scholar
Hagerman, R. J. (1989a) Behaviour and treatment of the fragile X syndrome. In The Fragile X Syndrome (ed. Davies, K. E.). Oxford: Oxford University Press.Google Scholar
Hagerman, R. J. (1989b) Genes and chromosomes in autism. In Diagnosis and Treatment of Autism (ed. Gillberg, C.). New York: Plenum.Google Scholar
Hagerman, R. J., Kemper, M. & Hudson, M. (1985) Learning disabilities and attentional problems in boys with the fragile X syndrome. American Journal of Diseases of Children, 139, 674–678.Google Scholar
Hagerman, R. J., Jackson, A. W., Levitas, A., et al (1988a) Oral folic acid versus placebo in the treatment of males with the fragile X syndrome. American Journal of Medical Genetics, 23, 241–262.Google Scholar
Hagerman, R. J., Jackson, A. W., Levitas, A., et al (1986b) An analysis of autism in 50 males with the fragile X syndrome. American Journal of Medical Genetics, 23, 359–374.CrossRefGoogle ScholarPubMed
Hagerman, R. J., Berry, R., Jackson, A. W., et al (1988a) Institutional screening for the fragile X syndrome. American Journal of Diseases in Children, 142, 1216–1221.Google ScholarPubMed
Hagerman, R. J., Murphy, M. A. & Wittenberger, M. D. (1988b) A controlled trial of stimulant medication in children with the fragile X syndrome. American Journal of Medical Genetics, 30, 377–392.Google Scholar
Hagerman, R. J. & Sobesky, W. E. (1989) Psychopathology in fragile X syndrome. American Journal of Orthopsychiatry, 59, 142–152.Google Scholar
Hagerman, R. J., Schreiner, R. A., Kemper, M. B., et al (1989) Longitudinal IQ changes in fragile X males. American Journal of Medical Genetics, 33, 513–518.Google Scholar
Hanson, D. M., Jackson, A. W. & Hagerman, R. J. (1986) Speech disturbances (cluttering) in mildly impaired males with the Martin–Bell/fragile X syndrome. American Journal of Medical Genetics, 23, 195–206.Google Scholar
Herbst, D. S. & Miller, J. R. (1980) Nonspecific X-linked mental retardation II: The frequency in British Columbia. American Journal of Medical Genetics, 7, 461–469.Google Scholar
Hockey, A. & Crowhurst, J. (1988) Early manifestations of the Martin-Bell syndrome based on a series of both sexes from infancy. American Journal of Medical Genetics, 30, 61–71.Google Scholar
Howard-Peebles, P. N. & Stoddard, G. R. (1979) X-linked mental retardation with macroorchidism and marker X chromosomes. Human Genetics, 50, 247–251.Google Scholar
Kemper, M. B., Hagerman, R. J., Ahmad, R. S., et al (1986) Cognitive profiles and the spectrum of clinical manifestations in heterozygous fra(X) females. American Journal of Medical Genetics, 23, 139–156.Google Scholar
Kemper, M. B., Hagerman, R. J. & Altshul-Stark, D. (1988) Cognitive profiles of boys with the fragile X syndrome. American Journal of Medical Genetics, 30, 191–200.Google Scholar
Lachiewicz, A. M., Gullion, C. M., Spiridigliozzi, G. A., et al (1987) Declining IQs of young males with the fragile X syndrome. American Journal of Mental Retardation, 92, 272–278.Google Scholar
Laird, C. D. (1987) Proposed mechanism of inheritance and expression of the human fragile-X syndrome of mental retardation. Genetics, 117, 587–599.Google Scholar
Largo, R. H. & Scmnzel, A. (1985) Developmental and behavioural disturbances in 13 boys with fragile X syndrome. European Journal of Pediatrics, 143, 269–275.Google Scholar
Ledbetter, D. H., Ledbetter, S. A. & Nussbaum, R. L. (1986) Implications of fragile X expression in normal males for the nature of the mutation. Nature, 324, 161–163.Google Scholar
Lejeune, J. (1982) Is the fragile X syndrome amenable to treatment? Lancet, i, 273–274.Google Scholar
Levitas, A., McBogg, P. & Hagerman, R. (1983) Behavioral dysfunction in the fragile X syndrome. In The Fragile X Syndrome – Diagnosis, Biochemistry, and Intervention (eds Hagerman, R. J. & McBogg, P. M.). Dillon, Colorado: Spectra.Google Scholar
Loesch, D. Z., Hay, D. A., Sutherland, G. R., et al (1987) Phenotypic variation in male-transmitted fragile X: genetic inferences. American Journal of Medical Genetics, 27, 401–417.CrossRefGoogle ScholarPubMed
Loesch, D. Z. & Wilson, S. R. (1989) Multivariate analysis of body shape in fragile X (Martin-Bell) syndrome. American Journal of Medical Genetics, 33, 200–208.Google Scholar
Mattei, J. F., Mattei, M. G., Aumeras, C., et al (1981) X-linked mental retardation with the fragile X. A study of 15 families. Human Genetics, 59, 281–289.Google Scholar
McConaughy, S. H. & Achenbach, T. M. (1988) Practical Guide for the Child Behavior Checklist and Related Materials. Burlington: University of Vermont Department of Psychiatry.Google Scholar
McGavran, L. & Maxwell, F. (1983) Cytogenetic aspects of the fragile X syndrome. In The Fragile X Syndrome – Diagnosis, Biochemistry, and Intervention (eds Hagerman, R. J. & McBogg, P. M.). Dillon, Colorado: Spectra.Google Scholar
McGillivray, B. C., Herbst, D. S., Dill, F. J., et al (1986) Infantile autism: an occasional manifestation of fragile (X) mental retardation. American Journal of Medical Genetics, 23, 353–358.Google Scholar
McGlaughlin, J. F. & Kriegsman, E. (1980) Developmental dyspraxia in a family with X-linked mental retardation (Renpenning syndrome). Developmental Medicine and Child Neurology, 22, 84–92.Google Scholar
McKinley, M. J., Kearney, L. U., Nicolaides, K. H., et al (1988) Prenatal diagnosis of fragile X syndrome by placental (chorionic villi) biopsy culture. American Journal of Medical Genetics, 30, 355–368.Google Scholar
Meryash, D. L., Szymanski, L. S. & Gerlad, P. S. (1982) Infantile autism associated with the fragile-X syndrome. Journal of Autism and Developmental Disorders, 12, 295–301.Google Scholar
Miezejeski, C. M., Jenkins, E. C., Hill, A. L., et al (1986) A profile of cognitive deficit in females from fragile X families. Neuropsychologic, 24, 405–409.Google Scholar
Musumeci, S. A., Colognola, R. M., Gigli, G. L., et al (1988) Fragile-X syndrome: a particular epileptogenic EEG pattern. Epilepsia, 29, 41–47.Google Scholar
Neri, G., Sanfilippo, S., Pavone, L., et al (1988) The fragile X in Sicily: an epidemiological survey. American Journal of Medical Genetics, 30, 665–672.Google Scholar
Newell, K., Sanborn, B. & Hagerman, R. (1983) Speech and language dysfunction in the fragile X syndrome. In The Fragile X Syndrome – Diagnosis, Biochemistry, and Intervention (eds Hagerman, R. J. & McBogg, P. M.). Dillon, Colorado: Spectra.Google Scholar
Nussbaum, R. L. & Ledbetter, D. H. (1986) Fragile X syndrome: a unique mutation in man. Annual Review of Genetics, 20, 109–145.Google Scholar
Opitz, J. M., Westphal, J. M. & Daniel, A. (1984) Discovery of a connective tissue dysplasia in the Martin-Bell syndrome. American Journal of Medical Genetics, 17, 101–109.Google Scholar
Payton, J. B., Steele, M. W., Wenger, S. L., et al (1989) The fragile X marker and autism in perspective. Journal of the American Academy of Child and Adolescent Psychiatry, 28, 417–421.Google Scholar
Pembrey, M. E., Winter, R. M. & Daves, K. A. (1985) A premutation that generates a defect at crossing over explains the inheritance of fragile X mental retardation. American Journal of Medical Genetics, 21, 709–717.Google Scholar
Pembrey, M. E., Winter, R. M. & Daves, K. A. (1986) Fragile X mental retardation: current controversies. Trends in Neurosciences, 9, 58–62.Google Scholar
Pueschel, S. M., Herman, R. & Groden, G. (1985) Screening children with autism for fragile-X syndrome and phenylketonuria. Journal of Autism and Developmental Disorders, 15, 335–338.Google Scholar
Redington, A. & Bush, A. (1990) Fragile X mental retardation. Archives of Disease in Childhood, 65, 335.Google Scholar
Reiss, A. L., Feinstein, C., Toomey, K. E., et al (1986) Psychiatric disability associated with the fragile X syndrome. American Journal of Medical Genetics, 23, 393–401.Google Scholar
Reiss, A. L., Hagerman, R. J., Vinogradov, S., et al (1988a) Psychiatric disability in female carriers of the fragile X chromosome. Archives of General Psychiatry, 45, 25–30.Google Scholar
Reiss, A. L., Patel, S., Kumar, A. J., et al (1988b) Preliminary communication: neuroanatomical variations of the posterior fossa in men with the fragile X (Martin-Bell) syndrome. American Journal of Medical Genetics, 31, 407–414.Google Scholar
Reiss, A. L., Freund, L., Vinogradov, S., et al (1989) Parental inheritance and psychological disability in fragile X females. American Journal of Human Genetics, 45, 697–705.Google ScholarPubMed
Reiss, A. L. & Freund, L. (1990) Fragile X syndrome. Biological Psychiatry, 27, 223–240.Google Scholar
Rogers, R. C. & Simensem, R. J. (1987) Fragile X syndrome: a common etiology of mental retardation. American Journal of Mental Deficiency, 91, 445–449.Google Scholar
Rudelli, R. D., Jenkins, E. C., Wisniewski, K., et al (1983) Testicular size in fetal fragile X syndrome. Lancet, i, 1221–1222.Google Scholar
Rutter, M., Macdonald, H., Le Couteur, A., et al (1990) Genetic factors in child psychiatric disorders – II. Empirical findings. Journal of Child Psychology and Psychiatry, 31, 39–83.Google Scholar
Simko, A., Hornstein, L., Soukup, S., et al (1989) Fragile X syndrome: recognition in young children. Pediatrics, 83, 547–552.Google Scholar
Sreeram, N., Wren, C., Bhate, M., et al (1989) Cardiac abnormalities in the fragile X syndrome. British Heart Journal, 61, 289–291.Google Scholar
Sutherland, G. R. (1977) Fragile sites on human chromosomes: demonstration of their dependence on the type of tissue culture medium. Science, 197, 265–266.Google Scholar
Sutherland, G. R. (1982) Heritable fragile sites on human chromosomes. VIII. Preliminary population cytogenetic data on the folic-acid-sensitive fragile sites. American Journal of Human Genetics, 34, 452–458.Google Scholar
Thake, A., Todd, J., Bundey, S., et al (1985) Is it possible to make a clinical diagnosis of the fragile X syndrome in a boy? Archives of Disease in Childhood, 60, 1001–1007.Google Scholar
Thake, A., Todd, J., Webb, T., et al (1987) Children with the fragile X chromosome at schools for the mildly mentally retarded. Developmental Medicine and Child Neurology, 29, 711–719.Google Scholar
Theobald, T. M., Hay, D. A. & Judge, C. (1987) Individual variation and specific cognitive deficits in the fragile X syndrome. American Journal of Medical Genetics, 28, 1–11.Google Scholar
Tommerup, N. (1989) Cytogenetics of the fragile site at Xq27. In The Fragile X Syndrome (ed. Davies, K. E.). Oxford: Oxford University Press.Google Scholar
Turk, J. (1989) Hyperactivity, conduct disturbances and the fragile X syndrome. First World Congress of Psychiatric Genetics; Abstracts. Southampton: Duphar.Google Scholar
Turner, G., Daniel, A. & Frost, M. (1980) X-linked mental retardation, macro-orchidism, and the Xq27 fragile site. Journal of Pediatrics, 96, 837–841.Google Scholar
Turner, G. & Jacobs, P. (1983) Marker (X)-linked mental retardation. In Advances in Human Genetics, vol. 13 (eds Harris, H. & Hirschorn, K.). New York: Plenum.Google Scholar
Veenema, H., Veenema, T. & Geraedts, J. P. M. (1987) The fragile X syndrome in a large family. II Psychological investigations. Journal of Medical Genetics, 24, 32–38.Google Scholar
Venter, P. A., Opt Hof, J., Coetzee, D. J., et al (1984) No marker (X) syndrome in autistic children. Human Genetics, 67, 107.Google Scholar
Verkerk, A. J. M. H., Pieretti, M., Sutcliffe, J. S., et al (1991) Identification of a gene (FMR-1) containing a CGG repeat coincident with a breakpoint cluster region exhibiting length variation in fragile X syndrome. Cell, 65, 905–914.Google Scholar
Vilkman, E., Niemi, J. & Ikonen, U. (1988) Fragile X speech phonology in Finnish. Brain Language, 34, 203–221.Google Scholar
Wahlstrom, J., Gillberg, C., Gustavson, K., et al (1986) Infantile autism and the fragile X. A Swedish multicenter study. American Journal of Medical Genetics, 23, 403–408.Google Scholar
Watson, M. S., Leckman, J. F., Annex, B., et al (1984) Fragile X in a survey of 75 autistic males (letter). New England Journal of Medicine, 310, 1462.Google Scholar
Webb, T. P., Bundey, S., Thake, A., et al (1986) The frequency of the fragile X chromosome among schoolchildren in Coventry. Journal of Medical Genetics, 23, 396–399.Google Scholar
Wing, L. & Gould, J. (1979) Severe impairments of social interactions and associated abnormalities in children: epidemiology and classification. Journal of Autism and Developmental Disorders, 9, 11–29.Google Scholar
Wolff, P. H., Gardner, J., Paccia, J., et al (1989) The greeting behaviour of fragile X males. American Journal of Mental Retardation, 93, 406–411.Google Scholar
Wright, H. H., Young, S. R., Edwards, J. G., et al (1986) Fragile-X syndrome in a population of autistic children. Journal of the American Academy of Child Psychiatry, 25, 641–644.Google Scholar
Submit a response

eLetters

No eLetters have been published for this article.