Affected First-Degree Relatives is a Risk Factor for Curve Progression in Subjects with Adolescent Idiopathic Scoliosis.

Introduction: Previous reports showed that AIS subjects with family history (fAIS) were different in clinical manifestation from those without (sAIS; sporadic). It is suggested that abnormal skeletal growth is involved in the etiopathogenesis and characteristics. It is speculated that fAIS and sAIS differ in phenotypic expressions related to skeletal growth which underlies the possible different in their pathogenesis. Objective: To uses retrospective epidemiological approach to compare the phenotypes and curve progression between the fAIS and sAIS. Materials and Methods: From the region-wide school screening program, 882 girls with AIS referral were recruited. Family history questionnaire and clinical assessment were taken twice at: 1) the first clinic visit; 2) the visit when reaching skeletal maturity. Curve progression and anthropometric parameters were recorded. Results: About 18% of AIS patients had at least one affected first-degree relatives. It was significantly more frequent for fAIS (odd ratio: 1.31; CI: 1.13-153) to have curve progression when compared with sAIS (p<0.001). fAIS was more likely to require bracing or surgery. fAIS had a significantly longer arm span and radius length than the sAIS while other anthropometric and clinical features were comparable. Conclusion: Among AIS patients with clinically significant curve, the prevalence of fAIS was 18%. Differences in curve severity and curve progression between fAIS and sAIS could be a reflection of underlying differences in etiopathogenesis of AIS. Significance: AIS subjects could be characterized into subgroups according to various genetic and phenotypic expressions. The further research into different subgroups of AIS subject would shed light to the eitopathogenesis of AIS. [ABSTRACT FROM AUTHOR]