Segmental costovertebral malformations: association with neural tube defects. Report of 3 cases and review of the literature.

Patients with spondylocostal dysostosis (SCD) have vertebral abnormalities and numerical or structural rib anomalies that produce thoracic asymmetry. Rib anomalies and dysmorphism are the typical features that differentiate this syndrome from spondylothoracic dysostosis (STD). Jarcho-Levin syndrome is a severe form with involvement of the whole vertebral column. Other associated findings such as congenital heart defects, abdominal wall malformations, genitourinary malformations and upper limb anomalies may be found; in addition, neural tube defects (NTDs) have been associated with this malformation. SCD is transmitted both in a recessive form and as a dominant defect. We report on 3 children with SCD; 2 also had NTDs. All of them were studied with X-rays and spinal magnetic resonance (MR), and over the same period they underwent multidisciplinary clinical functional evaluation. One of our cases with NTD also presented polythelia, which has not previously been described in patients with SCD. The common association of segmental costovertebral malformations with NTDs could be related to an early gastrulation genomic defect, or one after gastrulation, when there are two independent somitic columns. The latter sometimes progresses and then involves primary and secondary neurulation. Also, the association of SCD with NTDs could be related to the interaction of different genes, resulting in this complex phenotype. Therefore, additional genetical and embryological studies are necessary to provide evidence of an etiological link between SCD and NTD.