title: Behavioral phenotype in the 9q subtelomeric deletion syndrome: a report about two adult patients.
abstract: The 9q Subtelomeric Deletion Syndrome (9qSTDS) is clinically characterized by mental retardation, childhood hypotonia, and facial dysmorphisms. Haploinsufficiency of the EHMT1 gene has been demonstrated to be responsible for its core phenotype. In a significant number of patients behavioral abnormalities like aggression, impulsivity, and chaotic behaviors are present as well as epileptic phenomena. Reports about the developmental, behavioral, and neuropsychiatric aspects of 9qSTDS are scarce and mostly limited to young patients only. In this report, the behavioral and neuropsychiatric characteristics of one male and one female middle-aged patient are described in whom the genetic diagnosis, interstitial and telomeric 9q deletion, respectively, was established recently. In both patients a remarkable sleep disturbance, characterized by frequent awakenings and daytime sleepiness, was present as well as a prominent apathy syndrome. The observed motor signs such as rigid flexure of the arms and finger stereotypies persisted over a period of many years and could therefore not be viewed as symptoms of catatonia. It is concluded that the proposed behavioral phenotype of 9qSTDS comprises at least an erratic sleep pattern and an enduring severe apathy.
authors.affiliation: Vincent van Gogh Institute for Psychiatry, Centre of Excellence for Neuropsychiatry, Venray, The Netherlands.|Department of Psychiatry, Erasmus University Medical Centre, Rotterdam, The Netherlands.
authors.forename: Willem M A
authors.initials: WMA
authors.lastname: Verhoeven
authors.affiliation: Department of Human Genetics, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
authors.forename: Tjitske
authors.initials: T
authors.lastname: Kleefstra
authors.affiliation: Vincent van Gogh Institute for Psychiatry, Centre of Excellence for Neuropsychiatry, Venray, The Netherlands.|Department of Clinical Psychology, Behavioural Science Institute, Radboud University Nijmegen, Nijmegen, The Netherlands.
authors.forename: Jos I M
authors.initials: JIM
authors.lastname: Egger
mesh_terms: D001519:Behavior; D001842:Bone and Bones / Q000473:pathology; D002872:Chromosome Deletion; D002899:Chromosomes, Human, Pair 9; D005260:Female; D006801:Humans; D008607:Intellectual Disability / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D008957:Models, Genetic; D009123:Muscle Hypotonia / Q000235:genetics*; D009426:Netherlands; D010641:Phenotype; D013577:Syndrome; D016615:Telomere / Q000648:ultrastructure*