The following are the most important diseases or complications that may be contributed to by Klinefelter syndrome:
Congenital malformations, deformities, and chromosomal abnormalities (Q00-Q99).
- Positional anomalies of the testes (testes).
Respiratory system (J00-J99)
- Bronchiectasis (synonym: bronchiectasis) – persistent irreversible saccular or cylindrical dilatation of the bronchi (medium-sized airways) that may be congenital or acquired; symptoms: chronic cough with “mouthladen expectoration” (large-volume triple-layered sputum: foam, mucus, and pus), fatigue, weight loss, and decreased exercise capacity
- Pulmonary emphysema – irreversible hyperinflation of the smallest air-filled structures (alveoli, alveoli) of the lungs.
Endocrine, nutritional and metabolic diseases (E00-E90).
- Obesity (obesity)
- Diabetes mellitus type 2 (diabetes)
- Metabolic syndrome – clinical name for the symptom combination obesity (overweight), hypertension (high blood pressure), increased fasting glucose (fasting blood sugar) and fasting insulin serum levels (insulin resistance) and lipid metabolism disorder (increased VLDL triglycerides, decreased HDL cholesterol). Furthermore, a coagulation disorder (increased tendency to clotting), with an increased risk of thromboembolism is also often detectable
Cardiovascular system (I00-I99)
- Pulmonary embolism (obstruction of a pulmonary artery).
- Thromboembolism – departure of a blood clot that clogs a vessel in the bloodstream, leading to circulatory problems with tissue destruction
- Varices (varicose veins)
Musculoskeletal system and connective tissue (M00-M99)
- Osteopenia (reduction in bone density).
- Osteoporosis (bone loss)
Neoplasms – tumor diseases (C00-D48)
- Extragonadal (outside the gonads) nonseminomatous germ cell tumors in the mediastinum (middle pleural space, i.e., a vertically running tissue space in the thoracic cavity) [Occurrence between the ages of 15 and 30].
- Mammary carcinoma (breast cancer) (about 50-fold increased risk → participation in a mammography screening is useful).
Psyche – nervous system (F00-F99; G00-G99).
- Epilepsy
- Dyslexia
- Learning disability (mental retardation; delayed verbalization; language disorder).
Genitourinary system (kidneys, urinary tract – reproductive organs) (N00-N99).
- Gynecomastia (enlargement of the mammary glands).
Injuries, poisonings, and certain other consequences of external causes (S00-T98).
- Fracture of the neck of the femur (SHF, femoral neck fracture).
