©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 18 (2): gmr18246 Lack of differences in the expression of the angiotensin I - converting enzyme gene in the rotator muscles of patients with adolescent idiopathic scoliosis in a cross- sectional study comparing between the concave and convex sides of the scoliosis. M. Wajchenberg 1,2 , D.E. Martins 1,2 , R.P. Luciano 1 , R.C. Araujo 1 , B. Schmidt 1 , A.B.S. Oliveira 1 , E.B. Puertas 1 , S.S. Almeida 1,2 and F. Faloppa 1 1 Universidade Federal de São Paulo, Departamento de Traumatologia e Ortopedia, São Paulo, SP, Brasil 2 Hospital Israelita Albert Einstein, São Paulo, SP, Brasil Corresponding author: M. Wajchenberg E-mail: marcelow@einstein.br Genet. Mol. Res. 18 (2): gmr18246 Received November 14, 2018 Accepted April 08, 2019 Published April 30, 2019 DOI http://dx.doi.org/10.4238/gmr18246 ABSTRACT. Several theories have been proposed to explain the etiology of adolescent idiopathic scoliosis (AIS), but none is conclusive. One such theory suggests the primary involvement of muscles due to myopathy, mainly affecting the erector and paravertebral rotator muscles. Studies indicate that there may be an association of AIS with genetic polymorphisms previously associated with physical performance and muscle power through their effects on muscle tissue. One of these is the gene coding for the angiotensin converting enzyme (ACE). We compared the expression of ACE gene polymorphisms in the concave and convex sides of the scoliotic curve in patients with AIS. We evaluated ACE gene expression in the multifidus muscles of the spine of 21 patients operated for AIS correction who had signs of asymmetric myopathy (worse in the concavity). Tissue samples were collected during corrective surgery. There was no significant difference in ACE gene expression in multifidus muscle samples from the two sides of the apex of the thoracic AIS deformity. There were also no differences in the expression of insertion/deletion polymorphisms.