Defecto de la Zona de Desarrollo primaria del esqueleto axial (Síndrome de Jarcho–Levin, “Fenotipo Jarcho–Levin”)

Abstract

We have used data from the Spanish Collaborative Study of Congential Malformations (ECEMC), to epidemiologically analyze anomalies of the axial skeleton, from the clinical, etiological and pathogenetic points of view. Since 1980, a total of 1,847,301 newborn infants were surveyed. Among them, 31,604 were malformed. In 283 infants, anomalies of the spine and/or ribs were observed. The ECEMC´s coding system includes several levels to code defects and patterns of anomalies. This made the present analysis possible. In the first level, each specific defect is coded. The second level has three sublevels to define the global pattern of defects of each infant, as well as the different types of patterns that can be distinguished in infants with multiple defects, whether with or without having a diagnosis of some particular syndrome. This coding system allows to study specific defects or pattern of defects, according with the most modern dysmorphologic concepts. After applying this system to axial skeleton anomalies, we observed that among infants with isolated defects, only 0.14% had the axial skeleton affected. This percentage is higher among infants with MCA patterns (3.59%) and syndromes (1.91%). It is clear the great clinical and causal heterogeneity of these costal–vertebral anomalies. This supports our previous conclusion [Am J Med Genet 1994; 49: 36–44], on that axial skeleton anomalies are one of the results of the dysmorphogenetic reaction of the primary field, which is the whole embryo during blastogenesis. Therefore, the terms spondylo–thoracic dysplasia, spondylocostal dysplasia, costovertebral dysplasia, crab–like thorax, among others, are not diagnoses but different names for the diverse expressions of the primary developmental field of the axial skeleton. It is important the proper use of terminology, based on the current knowledge of developmental biology, in order to provide adequate counselling to families.