GDF9 and galactosemia: Other reasons include genetic disorders (Turner's syndrome, bone morphogenetic protein 15 (BMP15) mutation, galactosemia, mutation of forkhead box protein L2 (FOXL2), growth differentiation factor-9 (GDF9), mutation of luteinizing hormone (LH) and follicle-stimulating hormone receptors (FSHR), etc.), enzymatic mutation such as aromatase, autoimmune disorders (Addison's disease, vitiligo, systemic lupus erythematosus, myasthenia gravis, autoimmune thyroiditis, autoimmune polyglandular syndrome, etc.), vaccination, and environmental factors (cigarette smoking, toxins, and infections).