Our case control study was conducted on 32 children and adolescents with Autoimmune Thyroiditis attending the Pediatric Endocrinology Clinic of Assiut University Children Hospital, Assiut, Egypt. . Diagnosis of Autoimmune Thyroiditis had been made by elevated anti-thyroid peroxidase antibodies (TPO Ab) and/or anti-thyroglobulin antibodies (Tg Ab) as well as typical hypoechogenicity of the thyroid in high-resolution sonography . Another group of 32 age and sex-matched healthy subjects as a control group.