The familiarity of idiopathic scoliosis: statistical analysis and clinical considerations.

Abstract PURPOSE: The etiology of idiopathic scoliosis (IS) has been the subject of extensive research, and the current opinion is in favor of a multifactorial pathogenesis with an important genetic component. The aim of this study is to investigate the pattern of inheritance over generations of IS and its possible risk factors. METHODS: A total of 70 patients affected by IS was selected and studied up to the third generation for an overall cohort of 2,055 subjects. The genealogy was investigated and correlated for scoliosis. RESULTS: The outcomes showed that 73 % of the patients had an age between 12 and 15 years. The 60 % of the mothers had an age between 20 and 29 years and 57 % of the patients were "first born". The 5.8 % of the brothers and the 12.7 % of the sisters were affected by scoliosis. From the analysis of the total sample, it is clear that in 53 % of the families, there is at least another scoliotic besides the patient. CONCLUSION: The statistical analysis revealed three different types of transmission: autosomic dominant, autosomic recessive and multifactorial. When this last mode of inheritance is involved, female sex and firstborn resulted as risk factors of IS.