Klinefelter Syndrome is an inherited disorder of the sex chromosome in which an extra X chromosome is present (XXY)Klinefelter syndrome is a genetic disorder that happens in males with an extra X chromosome.It happens in males and is linked with hypo-gonads and infertility.Klinefelter syndrome happens in about 1 out of 500 to 1,000 baby boys.CauseNormal people have 46 chromosomes.Chromosomes hold all of the genes and DNA, the building blocks of the body.The 2 sex chromosomes (X and Y) decide if the baby becomes a boy or a girl.Girls normally have 2 X chromosomes.Boys normally have 1 X and 1 Y chromosome.Klinefelter syndrome occurs when a boy is born with at least 1 extra X chromosome.Normally, this happens due to 1 extra X chromosome.This is recorded as XXY.The testis formation is involved leading to hypo-gonadism and low testosterone secretion.Symptoms may be:1. Disproportionate body appearances (long legs, short trunk, shoulder equal to hip size)2. Abnormally large breasts in boys (gynecomastia) in 50 per cent3. Infertility4. Sexual problems - Sexual desire and ability to have erections impaired5. Penis is small6. Testes are small, insensitive and firmer than usual7. Less than normal amount of pubic, armpit, and facial hair8. Tall height9. Weaker muscles10. Language learning or reading impairment may be presentDiagnosis of Klinefelter Syndrome is often based on1. Medical examination of appearance2. Buccal smear for cells to test for chromosones3. Karyotyping (checking the chromosomes)4. Semen countBlood tests will be done to check hormone levels such as:5. Blood test for testosterone (low),6. Blood follicle stimulating hormone (raised),7. Blood luteinizing hormones (raised or normal)8. Blood estradiol, a type of estrogen (raised)9. Urinary gonadotropins are raised due to abnormal Leydig cell functionTreatment should focus on 3 major facets of the syndrome:1. Hypo-gonadism,2. Gynecomastia, and3. Psychosocial problems1. Male hormone treatment (testosterone) can help:a. Grow body hairb. Improve appearance of musclesc. Improve concentrationd. Improve mood and self esteeme. Increase energy and sex drivef. Increase strengthIn most cases testosterone is started at puberty, around age 12 yearsRegular testosterone injections can also:a. Increase strength and facial hair growth;b. Improve a more muscular body type;c. Raise sexual desire;d. Enlarge the testes;e. Improve mood, self-image, and behavior; andf. Protect against precocious osteoporosis.Testosterone therapy does not treat infertility or gynecomastiaSpeech, physical and behavioral therapy helps.Physical therapy is advised for boys with hypo-tonia or delayed gross motor skills that may involve muscle tone, balance, and coordination.Occupational therapy is advised in boys with motor dyspraxia (a developmental disorder of the brain in childhood causing difficulty in activities requiring coordination and movement).TABLE OF CONTENTIntroductionChapter 1 Klinefelter SyndromeChapter 2 CausesChapter 3 SymptomsChapter 4 DiagnosisChapter 5 TreatmentChapter 6 PrognosisChapter 7 Lynch SyndromeChapter 8 Marfan SyndromeEpilogue