Congenital long QT syndrome

Artículo especialThe long QT syndrome (LQTS) is an hereditary disease that produces a malfunction on the sodium and potassium channels of the heart and lengthens the duration of the cardiac repolarization stage. It is characterized by the appearance of syncopes, arrhythmias and even sudden death. There are two variants of the congenital LQTS: the autosomal dominant Romano-Ward syndrome and the autosomal recessive Jervell-Lange-Nielsen syndrome, that is associated with sensorineural deafness and is less frequent than the other type. The diagnosis is made from the clinical criteria, the electrocardiogram and the family history. In the last few years, molecular studies have been developed, opening new possibilities not only for its diagnosis but also for the treatment of these patients.N

Very low frequency Syndromes

Dismorfología, Citogenética y Clínica: Resultados de estudios sobre los datos del ECEMCThe aim of this chapter is to summarize updated knowledge about the clinical characteristics, etiology, genetic and molecular aspects, as well as mechanisms involved in syndromes having very low frequency, in order to promote their better recognition. During the last five years, a total of 30 syndromes have been published in this chapter of the Boletín del ECEMC. This issue includes the following selected syndromes: Crouzon, Pfeiffer, Apert, Saethre-Chotzen, Carpenter and Muenke. All share craniosynostosis as the main clinical feature but also present with other birth defects, the most important being limb malformations, specially syndactyly and polydactyly. Over 100 syndromes with craniosynostosis have been described, usually involving multiple sutures, and several of them are associated with limb malformations. The clinical overlapping between those syndromes makes difficult to perform a neonatal diagnosis, based on their clinical findings. However, molecular genetic testing, specifically of the FRGR1-3 and TWIST1 genes, could help to establish the diagnosis of some of them. Early diagnosis is important for establishing the most suitable treatment for each patient, as well as to offer an accurate genetic counselling and the possibility of preimplantational and/or prenatal diagnosis.N