Case-Control Study Found No Link Between ABO Blood Type and Scoliosis Risk

Adolescent idiopathic scoliosis (AIS) represents a complex, three-dimensional structural spinal deformity affecting 1% to 3% of adolescents aged 10 to 16 years, and although genetic inheritance plays a pivotal role in disease development and the ABO blood group system serves as an established genetic marker across multiple diseases, its relationship with scoliosis risk has remained insufficiently investigated. Addressing this notable clinical gap, Bhavuk Garg and colleagues conducted a study aimed at evaluating the potential association between ABO blood group types and AIS susceptibility in surgically treated patients.

Therefore, the retrospective case-control study evaluated 133 surgically treated scoliosis patients with severe curvature (Cobb angle >45°) alongside 140 age- and sex-matched healthy controls. Researchers analyzed variations in ABO blood group distribution between the groups using Pearson’s chi-square tests and odds ratios with 95% confidence intervals.

Key Clinical Findings of the Study Includes:

• O-Positive Distribution: The study observed O-positive blood group prevalence reached 32.33% among scoliosis cases compared to control distribution patterns without achieving statistical significance (OR = 1.23, 95% CI 0.74–2.07; p = 0.882).

• B-Positive Proportion: The research identified the B-positive phenotype was present in 28.57% of affected adolescent patients, reflecting an equivalent baseline frequency in healthy control subjects.

• A-Positive Frequency: The analysis recorded an A-positive phenotype appeared in 24.81% of surgical candidates, demonstrating comparable proportions across both comparative cohorts.

• Minority Phenotypes: The investigation documented AB-positive at 10.52%, and Rhesus-negative blood types at 3.75% exhibited similar distribution frequencies between cases and control groups.

• Gender Comparison: The data confirmed that subgroup evaluation demonstrated that blood group distribution between male and female participants showed no statistically significant gender-based differences (p = 0.266).

The results suggest that no significant phenotypic association exists between ABO blood group classifications and the risk of adolescent idiopathic scoliosis in surgically treated patients, indicating that crude blood group distribution does not reflect underlying genomic risks in this complex polygenic disorder.

From a clinical perspective, these findings indicate that routine ABO blood group typing is not useful as an epidemiological screening or risk assessment tool for adolescent idiopathic scoliosis.

While the study is limited by its retrospective focus on a single cohort of surgically treated patients, future multicenter research across the full clinical spectrum of scoliosis using advanced genetic mapping is recommended to further clarify potential genomic correlations.

Reference

Garg, B., Jha, T., & George, J. (2026). Is ABO Blood Group a Risk Factor for Adolescent Idiopathic Scoliosis? Evidence from a Case–Control Study of Surgically Treated Patients. Indian Journal of Orthopaedics. Published online September 7, 2026.