Since the year 2002, this Section of the Boletín del ECEMC: Revista de Dismorfología y Epidemiología, is dedicated to dysmorphology, cytogenetics and clinical analysis of congenital anomalies, and includes a chapter on syndromes with very low frequency. The aim of this chapter is to summarize the most important characteristics, the etiology, and the mechanisms involved in the selected syndromes. The low frequency of these syndromes, together with their probable decreasing birth prevalence due to the impact of prenatal diagnosis, imply that pediatricians and other health professionals would have less opportunity to know their clinical characteristics. This circumstance together with the overlapping of the clinical features among some of the syndromes, make difficult to perform an early diagnosis, which is important for genetic counselling, and to provide the most suitable treatment to each pacient. The syndromes included are: Aarskog, Freeman-Sheldon, Cleidocranial dysplasia, Noonan, Cardio-Facio-Cutaneous and Costello. In addition, a short summary about the differential diagnosis among Noonan, Cardio-Facio-Cutaneous and Costello syndromes is also included.
2008-10
