Cognitive and Behavioural Characterisitcs Of

COGNITIVE AND BEHAVIOURAL CHARACTERISITCS OF CHILDREN WITH SMITH-MAGENIS SYNDROME Thesis submitted for the degree of Doctorate in Clinical Psychology at the University of Leicester by Carolyn Webber BSc MSc Department of Psychology University of Leicester October 1999 UMI Number: U135663 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. Dissertation Publishing UMI U135663 Published by ProQuest LLC 2013. Copyright in the Dissertation held by the Author. Microform Edition © ProQuest LLC. All rights reserved. This work is protected against unauthorized copying under Title 17, United States Code. ProQuest LLC 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106-1346 ACKNOWLEDGEMENTS I would like to express my sincere gratitude to my project supervisor, Dr Orlee Udwin, for her tremendous support and advice over the last few years, and to Dr Keith Turner for his guidance and encouragement. Special thanks go to all the wonderful parents and children who welcomed me into their homes, without whose co-operation and enthusiasm this project would not have been possible. Finally, thank you to Miles and Tali for being so patient and understanding. ABSTRACT Cognitive and Behavioural Characteristics of Children with Smith-Magenis Syndrome by Carolyn Webber The study aimed to identify behavioural and cognitive characteristics in 29 children with Smith-Magenis syndrome. Cognitive assessments were undertaken on the children, and detailed interviews assessing sleep patterns, maladaptive behaviours, self-injury, hyperactivity and autism were carried out with their parents and teachers. The study identified high levels of sleep problems, aggression, self-injury, distractibility and autism in the sample, in comparison with rates reported for other groups of children with learning disabilities. These were associated with high levels of stress in the parents. It is concluded that the combination of difficulties and abilities identified in the present sample of children with SMS is indicative of a behavioural phenotype for the syndrome, and that there is an urgent need for intervention studies on the challenging behaviours posed by this group of children. CONTENTS Page Acknowledgements Abstract 1. INTRODUCTION 1 1.1 Introduction 1 1.2 Definition of Behavioural Phenotypes 2 1.3 Methods for Studying Behavioural Phenotypes 6 1.4 Clinical Applications of Behavioural Phenotype Research 10 1.5 Examples of Syndromes with a Distinct and Specific Behavioural Phenotype 11 1.6 Smith-Magenis Syndrome 19 1.7 Aims and Hypotheses of the Study 27 2. METHOD 30 2.1 Participants 30 2.2 Procedure 30 2.3 Measures 32 2.4 Data Analysis 42 3. RESULTS 44 3.1 Demographic Data 44 3.2 Cognitive Abilities and Attainment 49 3.3 Sleep Pattern and Difficulties 55 3.4 Aggressive Behaviour 65 3.5 Attention and Hyperactivity 78 3.6 Autism and Autistic Spectrum Disorders 79 3.7 Impact on the Family 83 Page 4. DISCUSSION 86 4.1 Methodological Issues 86 4.2 Intellectual and Cognitive Abilities 88 4.3 Sleeping Difficulties 90 4.4 Maladaptive Behaviours and Aggression 98 4.5 Attention and Hyperactivity 106 4.6 Autism 107 4.7 Other Behavioural Features 111 4.8 Impact on the Family 111 5. CONCLUSIONS 113 6. REFERENCES 115 7. APPENDIX 137 LIST OF TABLES Page Table 1. Demographic information 44 Table 2. Living arrangements 45 Table 3. Type of school attending 46 Table 4. Medical problems 48 Table 5. Distribution of IQ scores on the WISC-IH 50 Table 6. Mean scaled scores and standard deviations of the subtests of the WISC-m 50 Table 7. Age equivalent scores on Attainments tests 52 Table 8. Ages and IQ (scaled scores) of the readers versus non-readers, and spellers versus non-spellers 52 Table 9. Special skills 54 Table 10. Effective teaching strategies 55 Table 11. Type and frequency of sleep problem 56 Table 12. Sleep cycle 56 Table 13. Frequency of early waking 58 Table 14. Additional sleep related difficulties 59 Table 15. Effectiveness of intervention (for sleep problems) 61 Table 16. Type and efficacy of intervention for sleep difficulties 63 Table 17. Type, efficacy and side-effects of medication to facilitate sleep 64 Table 18. Parent’s reports of the prevalence of aggressive behaviours 66 Table 19. Triggers for aggressive behaviour 68 Table 20. Types of self-injurious behaviours displayed by the sample 70 Table 21. Frequency of self-injurious behaviours 72 Table 22. Triggers for self-injury 74 Table 23. Effective interventions for self-injurious behaviour 75 Table 24. Prevalence and degree of maladaptive behaviours 76 Table 25. Mean Developmental Behaviour Checklist Scores and Percentiles (Parents and Teachers) 77 Page Table 26. Prevalence of attention problems, impulsivity and restlessness according to parent responses from the PACS 79 Table 27. ‘Autistic Relating* subscale percentiles on the Developmental Behaviour Checklist 80 Table 28. Prevalence of specific autistic behaviours 82 Table 29. Response to peers/friendships 83 Table 30. Percentage of children showing frequent sleep problems and behaviours from Stores et al. 1996, and the present study 94 Table 31. Percentage scoring above the clinical cut-off on the Developmental Behaviour Checklist from various studies 101 Table 32. Comparison of Mean Developmental Behaviour Checklist scores for children with Fragile X syndrome, Williams syndrome and Learning Disabilities 102 Table 33. A comparison of self-injurious behaviour in children with Smith-Magenis syndrome and individuals with Learning Disabilities 103 LIST OF FIGURES Page Figure 1. Frequency of aggressive behaviours 65 Figure 2. Intensity of verbal aggression 66 Figure 3. Intensity of physical aggression 67 Figure 4. Intensity of aggression against property 67 1.1 INTRODUCTION Recent technological advances in molecular and clinical genetics have stimulated renewed interest in research focusing on genotype-phenotype associations in the field of learning disabilities. However, of 1000 known genetic causes of learning disabilities (Sarimski, 1997), most studies have concentrated on dysmorphic features of the physical phenotype, associated conditions and physical disabilities, and relatively few have detailed phenotypic workups (Sarimski, 1997). The new genetics and recent discoveries in specific syndrome groups highlight the importance of studies looking at the behavioural phenotype of various syndromes, and relating these findings to specific genetic features. For example, in fragile X syndrome, the most common inherited form of developmental delay, it has been suggested that variations in gene protein repeats are associated with within-syndrome variations in behaviour (Dykens, Hodapp & Leckman, 1994). It has been argued that behavioural investigations of specific syndromes could have far reaching implications: 'with accurate and thorough behavioural data, refined mappings can be made of specific genes associated with particular behaviours (Epstein et al., 1991).. .(and that).. .eventually, these mappings of gene functions may help develop various forms of gene therapies (Anderson, 1994)’. Smith-Magenis syndrome, a multiple congenital abnormality syndrome associated with learning disabilities and developmental delay, is caused by an interstitial deletion 1 of chromosome 17pl 1.2, and was first proposed by Smith, McGavran, Magenis et al. (1986). Although more than 100 cases have now been described in the literature, most published reports take the form of either single or small case series, describing variously the physical phenotype, and to a lesser degree some commonly found behavioural and cognitive characteristics. The largest systematic evaluation of individuals with the syndrome (n=27), reports the physical, medical and developmental characteristics but does not address behavioural characteristics (Greenberg, Lewis, Potocki et al., 1996). The present study seeks to add to currently available information about the cognitive and behavioural characteristics associated with the syndrome in childhood. Before reviewing the current literature on Smith- Magenis syndrome in more detail, it is useful to look at the theoretical applications of behavioural phenotypes. This chapter will examine various definitions of behavioural phenotypes, and consider methods for studying behavioural phenotypes, their use and clinical application. The chapter will conclude with a review of the current literature on Smith-Magenis syndrome and relate this to the aims and hypotheses of the current study. 1.2 Definition of Behavioural Phenotypes A phenotype is the “observable or measurable expression of a gene or genes” (Berini & Kahn, 1987). This broad definition applies to many groups, such as to “normal” individuals, those with psychiatric disorders, learning difficulties, and so on. The 2 study of behavioural phenotypes, however, is typically limited to “measurable expressions” in individuals with genetic disorders (O’Brien, 1992). Nyhan (1972) was the first to use the term ‘behavioural phenotype’. He suggested an association between an inborn error of purine metabolism and self-mutilatory behaviour in Lesch-Nyan syndrome. The behaviour seemed to relate to the underlying biological diagnosis and was relatively independent of environmental influences. Flint and Yule (1994) propose that the term behavioural phenotype

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