ABSTRACT
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.
Subject(s)
Angelman Syndrome/diagnosis , Angelman Syndrome/genetics , Prader-Willi Syndrome/diagnosis , Prader-Willi Syndrome/genetics , Algorithms , Child , Genotype , Humans , PhenotypeABSTRACT
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 mothers chromosome 15 causes PWSand gentic anomalies which affects the UBE3A gen mothers 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
