[From the clinical to the genetic diagnosis of Prader-Willi and Angelman syndromes]. / Del diagnóstico clínico al diagnóstico genético de los síndromes de Prader-Willi y Angelman.

INTRODUCTION AND DEVELOPMENT: Angelman syndrome (AS) is characterised by severe mental retardation (MR), the absence of language, ataxia and/or tremors in the extremities and a characteristic behavioural phenotype with a happy behaviour and hyperactivity. Patients often show signs of microcephaly and convulsions. Prader-Willi syndrome (PWS) is characterised by acute hypotonia and feeding problems in the neonatal period, and triggers an uncontrollable appetite in the infant that leads to obesity. Most patients have some degree of MR, behavioural disorders and hypogonadism. Both pathologies are caused by a number of genetic mechanisms that affect the 15q11-q13 region regulated by genomic imprinting, which means that only one of the two copies of the genes in this region will be functional, depending on which parent they come from. The physical or functional absence of genes that are only expressed by the mother's chromosome 15 causes PWS and gentic anomalies which affects the UBE3A gen mother's copy causes AS. CONCLUSIONS: It is important to confirm the clinical diagnosis and to establish the genetic mechanism responsible for the two syndromes, both for their consequences as regards the prognosis and for genetic counselling; it is therefore important to draw up a diagnostic algorithm.

Del diagnóstico clínico al diagnóstico genético de los síndromes de Prader-Willi y Angelman / From the clinical to the genetic diagnosis of prader-willi and angelman syndromes

Introduction and development. Angelman syndrome (AS) is characterised by severe mental retardation (MR), theabsence of language, ataxia and/or tremors in the extremities and a characteristic behavioural phenotype with a happybehaviour and hyperactivity. Patients often show signs of microcephaly and convulsions. Prader-Willi syndrome (PWS) ischaracterised by acute hypotonia and feeding problems in the neonatal period, and triggers an uncontrollable appetite in theinfant that leads to obesity. Most patients have some degree of MR, behavioural disorders and hypogonadism. Bothpathologies are caused by a number of genetic mechanisms that affect the 15q11-q13 region regulated by genomic imprinting,which means that only one of the two copies of the genes in this region will be functional, depending on which parent theycome from. The physical or functional absence of genes that are only expressed by the mother’s chromosome 15 causes PWSand gentic anomalies which affects the UBE3A gen mother’s copy causes AS. Conclusions. It is important to confirm theclinical diagnosis and to establish the genetic mechanism responsible for the two syndromes, both for their consequences asregards the prognosis and for genetic counselling; it is therefore important to draw up a diagnostic algorithm

Introducción y desarrollo. El síndrome de Angelman (SA)se caracteriza por retraso mental (RM) grave, ausencia del lenguaje,ataxia y/o temblores de las extremidades y un fenotipo conductualcaracterístico con conducta feliz e hiperactividad. Con frecuencialos pacientes presentan microcefalia y convulsiones. Elsíndrome de Prader-Willi (SPW) se caracteriza por una hipotoníaaguda y dificultades para la alimentación en el período neonatal, ypresenta en la infancia un apetito incontrolado que conduce a laobesidad. La mayoría de pacientes presentan algún grado de RM,problemas de comportamiento e hipogonadismo. Ambas patologíasestán causadas por varios mecanismos genéticos que afectan a laregión 15q11-q13 regulada por la impronta genómica, por lo quesólo una de las dos copias de los genes de esta región será funcionalsegún su origen parental. La ausencia física o funcional de genesque se expresan sólo del cromosoma 15 paterno causa el SPW yanomalías genéticas que afectan a la copia materna del gen UBE3Acausan el SA. Conclusión. Es importante confirmar el diagnósticoclínico y establecer el mecanismo genético responsable de ambossíndromes, por sus implicaciones pronósticas y para el consejo genético;por ello, es importante elaborar un algoritmo de diagnóstico

[Medical and behavioural aspects of Angelman syndrome]. / Aspectos médicos y conductuales del síndrome de Angelman.

INTRODUCTION: Angelman syndrome (AS) is a genetically-based disorder that is characterised by a physical and behavioural phenotype. Additionally, it presents a number of different systemic conditions that must also be taken into account. To evaluate the symptomatic spectrum of AS, we sought the aid of families linked to AS associations by sending them a questionnaire designed to investigate the clinical characteristics of AS. PATIENTS AND METHODS: The families were sent a questionnaire aimed at determining the medical and behavioural characteristics of AS. Results from 68 patients were analysed. RESULTS: The mean age at diagnosis was 4.8 years. The first symptoms that called parents' attention were feeding problems, followed by gastroesophageal reflux and hypotonia. The mean age at which patients were capable of maintaining a sitting posture was 18 months, while autonomous walking was not achieved until 43 months. Epilepsy, which was present in 91% of cases, began with febrile seizures in 55% of patients. In this study we found that a high percentage of patients with AS have a high resistance to pain (67%), a very common symptom in Prader-Willi syndrome, but little known in AS. CONCLUSIONS: This study offers a wide array of information about the clinical spectrum of AS obtained from an extensive populational sample. Some highly prevalent clinical aspects, such as the relative insensitivity to pain, have not been reported in previous publications as a symptom that is typical of AS.

Aspectos médicos y conductuales del síndrome de Angelman / Medical and behavioural aspects of angelman syndrome

Introducción. El síndrome de Angelman (SA) es un trastorno de base genética caracterizado por un fenotipo físico y conductual. Además, presenta diversas manifestaciones sistémicas que se deben tomar en consideración. Con el fin de valorar el espectro sintomático del SA, se solicitó la colaboración de familias vinculadas a asociaciones de SA mediante un cuestionario diseñado con base en las características clínicas del SA. Pacientes y métodos. Se envió a las familias un cuestionario orientado a determinar las características médicas y conductuales del SA. Se analizaron los resultados de 68 pacientes. Resultados. La edad media de diagnóstico fue de 4,8 años. Los síntomas más precoces que han llamado la atención a los padres son los problemas de alimentación, seguidos del reflujo gastroesofágico y la hipotonía. La edad media de adquisición de la sedestación es a los 18 meses, en tanto que la marcha autónoma no se adquiere hasta los 43 meses. La epilepsia, presente en el 91% de los casos, se inició con convulsiones febriles en el55%. En este estudio hemos hallado que un gran porcentaje de pacientes con SA presenta una elevada resistencia al dolor (67%),síntoma muy común en el síndrome de Prader-Willi, pero poco conocido en el SA. Conclusiones. Este estudio ofrece una amplia información sobre el espectro clínico del SA a partir de una extensa muestra poblacional. Algunos aspectos clínicos de elevada prevalencia, tales como la relativa insensibilidad al dolor, no se han recogido en publicaciones anteriores como síntoma propio del SA (AU)

Introduction. Angelman syndrome (AS) is a genetically-based disorder that is characterised by a physical and behavioural phenotype. Additionally, it presents a number of different systemic conditions that must also be taken into account. To evaluate the symptomatic spectrum of AS, we sought the aid of families linked to AS associations by sending them a questionnaire designed to investigate the clinical characteristics of AS. Patients and methods. The families were sent a questionnaire aimed at determining the medical and behavioural characteristics of AS. Results from 68 patients were analysed. Results. The mean age at diagnosis was 4.8 years. The first symptoms that called parents’ attention were feeding problems, followed by gastroesophageal reflux and hypotonia. The mean age at which patients were capable of maintaining asitting posture was 18 months, while autonomous walking was not achieved until 43 months. Epilepsy, which was present in91% of cases, began with febrile seizures in 55% of patients. In this study we found that a high percentage of patients with AS have a high resistance to pain (67%), a very common symptom in Prader-Willi syndrome, but little known in AS. Conclusions. This study offers a wide array of information about the clinical spectrum of AS obtained from an extensive populational sample. Some highly prevalent clinical aspects, such as the relative insensitivity to pain, have not been reported in previous publications as a symptom that is typical of AS (AU)