title: Development and behaviour in Marshall-Smith syndrome: an exploratory study of cognition, phenotype and autism.
abstract: BACKGROUND
  Marshall-Smith syndrome (MSS) is an infrequently described entity characterised by failure to thrive, developmental delay, abnormal bone maturation and a characteristic face. In studying the physical features of a group of patients, we noticed unusual behavioural traits. This urged us to study cognition, behavioural phenotype and autism in six patients.
  
  
  METHODS
  Information on development, behavioural characteristics, autism symptoms, and adaptive and psychological functioning of six MSS children was collected through in-person examinations, questionnaires, semi-structured interviews of parents and neuropsychological assessments.
  
  
  RESULTS
  Participants showed moderate to severe delays in mental age, motor development and adaptive functioning, with several similarities in communication, social interactions and behaviour. There was severe delay of speech and motor milestones, a friendly or happy demeanour and enjoyment of social interactions with familiar others. They exhibited minimal maladaptive behaviours. Deficits in communication and social interactions, lack of reciprocal social communication skills, limited imaginary play and the occurrence of stereotyped, repetitive behaviours were noted during assessments.
  
  
  CONCLUSIONS
  Systematic collection of developmental and behavioural data in very rare entities such as MSS allows recognition of specific patterns in these qualities. Clinical recognition of physical,developmental and behavioural features is important not only for diagnosis, prognosis and counselling of families, but also increases our understanding of the biological basis of the human physical and behavioural phenotype.
authors.affiliation: Jonx Department of Youth Mental Health, Lentis Psychiatric Institute, Zuidlaren, The Netherlands. idc.vanbalkom@lentis.nl
authors.forename: I D C
authors.initials: ID
authors.lastname: van Balkom
authors.forename: A
authors.initials: A
authors.lastname: Shaw
authors.forename: P J
authors.initials: PJ
authors.lastname: Vuijk
authors.forename: M
authors.initials: M
authors.lastname: Franssens
authors.forename: H W
authors.initials: HW
authors.lastname: Hoek
authors.forename: R C M
authors.initials: RC
authors.lastname: Hennekam
mesh_terms: D000015:Abnormalities, Multiple / Q000175:diagnosis* / Q000235:genetics* / Q000523:psychology; D000223:Adaptation, Psychological; D000293:Adolescent; D001321:Autistic Disorder / Q000175:diagnosis* / Q000235:genetics* / Q000523:psychology; D001848:Bone Diseases, Developmental / Q000175:diagnosis* / Q000235:genetics* / Q000523:psychology; D002648:Child; D002653:Child Behavior Disorders / Q000175:diagnosis* / Q000235:genetics* / Q000523:psychology; D002675:Child, Preschool; D003142:Communication; D019465:Craniofacial Abnormalities / Q000175:diagnosis* / Q000235:genetics* / Q000523:psychology; D004252:DNA Mutational Analysis; D002658:Developmental Disabilities / Q000175:diagnosis / Q000235:genetics / Q000523:psychology; D005260:Female; D006801:Humans; D008607:Intellectual Disability / Q000175:diagnosis* / Q000235:genetics* / Q000523:psychology; D008297:Male; D051839:NFI Transcription Factors / Q000235:genetics; D009460:Neurologic Examination; D009483:Neuropsychological Tests; D010552:Personality Assessment; D010641:Phenotype; D011379:Prognosis; D025962:Septo-Optic Dysplasia / Q000175:diagnosis* / Q000235:genetics* / Q000523:psychology
chemical_list: D051839:NFI Transcription Factors; C080333:transcription factor nuclear factor 1