Extra X Chromosomes B Physical Enlarged Breasts example essay topic

9 men with enlarged breasts, scanty facial / body hair, small testes, and infertility Klinefelter Syndrome I. History A. 1942, report published Klinefelter et al 9 men with enlarged breasts, scanty facial / body hair, small testes, and infertility B. 1959, condition named Klinefelter syndrome Men had extra sex chromosome (XXY), instead of XY C. Klinefelter is most common male chromosomal disorder linked to infertility and hypogonadism (small testes) II. Genetic information A. Typical karyotype: 47, XXY (80-90% patients) B. Variants to karyotype Mosaics (10%): 46, XY/47, XXY (fertility possible); 46, XY/48, Y; and 47, XXY/48, Y Remaining cases: 48, Y; 48 XXY; 49, Y; 49, Y 1%: structurally abnormal X addition to a normal XY C. Trait received by autosomal recessive inheritance D. Reciprocal X-Y interchange at paternal meiosis E. Onset: child born with condition, diagnosis occurs in adulthood. Characteristics A. Severity of symptoms is related to number of extra X chromosomes B. Physical Enlarged breasts, gynecomastia Fatigue, weakness Erectile dysfunction Osteoporosis Subnormal libido Taller than average male, long thin arms and legs Taurodontism (enlarged molar teeth) Sparse facial / body hair High-pitched voice Female-type fat distribution Small testes C. Cognitive Mental retardation Developmental and learning disabilities (academic problems, delayed speech, diminished short-term memory, attention deficit disorder, decreased data-retrieval skills, dyslexia) Behavioral problems and psychological distress due to poor self-esteem, poor psychosocial development, and decreased ability to deal with stress Psychiatric disorders: anxiety, depression, neurosis, psychosis D. Potentia consequences Infertility Risk of breast cancer is 20 X greater than normal male Cardiac / circulatory problems (mitral valve prolapse, varicose veins, venous ulcers, deep vein thrombosis, pulmonary embolism) Increased frequency of extra gonadal germ cell tumors IV. Treatment: 3 areas A. Hypogonadism and Gynecomastia Androgen therapy: testosterone replacement at puberty to correct androgen deficiency, provide virilization, and improve psychosocial status Regular testosterone injections to promote strength and hair growth, build muscle, increase libido, enlarge size of testes, improve overall mood and self-image, prevent osteoporosis Mastectomy to correct gynecomastia, reduce risk of breast cancer, and improve self-image B. Psychosocial problems Multidisciplinary team approach to work on speech impairments, academic difficulties, and other behavioral / psychosocial problems V. Miscellaneous A. Frequency: 1/500-1000 males B. Mortality: 40% males survive fetal period, normal life expectancy No racial predilection exists 9 men with enlarged breasts, scanty facial / body hair, small testes, and infertility.