Trisomy 18 syndrome Life-threatening disorder Description Second most common multiple malformation syndrome Full trisomy 18 in most affected infants: involves an extra (third) copy of chromosome 18 in each cell;…

Transposition of the great vessels Description Aorta rising from the right ventricle and the pulmonary artery from the left ventricle, producing two noncommunicating circulatory systems (see Looking at transposition of…

Tracheoesophageal fistula and esophageal atresia Life-threatening disorder Description Tracheoesophageal fistula: developmental anomaly characterized by an abnormal connection between the trachea and the esophagus; usually accompanies esophageal atresia, in which the…

Tonsillitis Description Inflammation of the tonsils May be acute or chronic Typical viral infection: mild and of limited duration Commonly affects children between ages 5 and 10 Pathophysiology Inflammatory response…

Thalassemia Description Group of genetic disorders characterized by defective synthesis in one or more of the polypeptide chains needed for hemoglobin (Hb) production Most commonly occurs as a result of…

Tetralogy of Fallot Description Combination of four heart defects: ventricular septal defect (VSD), right ventricular outflow tract obstruction (pulmonary stenosis), right ventricular hypertrophy, and overriding aorta (aorta positioned above the…

Tay-Sachs disease Life-threatening disorder Description Lipid storage disease that results from a congenital enzyme deficiency Leads to progressive mental and motor deterioration Always fatal, usually before age 5 About 100…

Sudden infant death syndrome Life-threatening disorder Description Sudden death of an infant younger than age 1 year without identifiable cause Occurs in approximately 2 out of every 1,000 live births;…