$Unique_ID{BRK04343} $Pretitle{} $Title{XYY Syndrome} $Subject{XYY Syndrome 47,XYY Syndrome 47,XYY Karyotype Polysomy Y Diplo-Y Syndrome YY Syndrome XYY Chromosome Pattern Klinefelter Syndrome Sotos Syndrome Marfan Syndrome Antisocial Personality Disorder } $Volume{} $Log{} Copyright (C) 1990, 1992 National Organization for Rare Disorders, Inc. 812: XYY Syndrome ** IMPORTANT ** It is possible that the main title of the article (XYY Syndrome) is not the name you expected. Please check the SYNONYM listing to find the alternate names and disorder subdivisions covered by this article. Synonyms 47,XYY Syndrome 47,XYY Karyotype Polysomy Y Diplo-Y Syndrome YY Syndrome XYY Chromosome Pattern Information on the following disorders can be found in the Related Disorders section of this report: Klinefelter Syndrome Sotos Syndrome Marfan Syndrome Antisocial Personality Disorder General Discussion ** REMINDER ** The information contained in the Rare Disease Database is provided for educational purposes only. It should not be used for diagnostic or treatment purposes. If you wish to obtain more information about this disorder, please contact your personal physician and/or the agencies listed in the "Resources" section of this report. XYY Syndrome is a rare chromosomal disorder which affects males. It is caused by the presence of an extra Y chromosome. Healthy males have one X and one Y chromosome. Men with XYY Syndrome are usually very tall and thin. Many have severe acne during adolescence. Other symptoms may include lower than average intelligence and antisocial or behavioral problems. Symptoms Characteristics of XYY Syndrome are often subtle and do not indicate a serious chromosomal disorder. Thus, males with this condition are often undiagnosed or misdiagnosed. Major symptoms may include tall or very tall height (usually becoming apparent after the age of 5 or 6), and severe cystic acne during adolescence. (For more information on cystic acne, choose "acne" as your search term in the Rare Disease Database). Lower than average intelligence, and/or behavioral problems (such as an explosive temper, aggressive or defiant actions, or sometimes antisocial behavior) are other symptoms. Some individuals with this disorder may have language difficulties or psychosexual problems. XYY Syndrome is often undiagnosed until tests for other medical reasons are performed. Other than being exceptionally tall and/or having behavioral problems, in many instances these boys or men appear normal. Physical characteristics of XYY Syndrome may include an unusually long head with a slightly protrusive forehead, long hands and feet, long ears, mild indentation in the lower area of the breastbone (pectus excavatum), and/or large teeth. Poor chest and shoulder muscle development (pectoral and shoulder girdle musculature) is also common. Even though males with this syndrome are large, they tend to be weak and uncoordinated. Some may have a fine intentional tremor (e.g. their hands may shake when they try to drink a glass of water). Occasionally, a bony formation across the joints in the two bones of the forearm resulting in stiffening of the affected joints (radioulnar synostosis) may occur. Other occasional symptoms are undescended testicles (cryptorchidism), a small penis, or an opening located on the underside of the penis (hypospadias). For a long time it was believed that XYY Syndrome individuals had aggressive tendencies often associated with criminal behavior due to the extra Y chromosome. Epidemiological studies suggest that one out of every 35 institutionalized male juvenile delinquents has XYY Syndrome. However, it is now believed by some researchers that this behavior is not due to the extra Y chromosome, but rather to the lower than average intelligence and education levels of these men. More research is needed to understand the role of this chromosomal abnormality on behavior. Causes XYY Syndrome is a genetic disorder caused by the presence of an extra Y chromosome. Normal males have 46 chromosomes including one X and one Y chromosome. Men with XYY Syndrome have 47 chromosomes, two of which are Y chromosomes. Why the extra Y chromosome occurs is not known. In very rare instances, the syndrome has been passed from father to son, but in most cases heredity cannot be established. Affected Population XYY Syndrome is a chromosomal disorder present at birth that affects only males. It is estimated to occur in approximately 1 of 1000 live births. Related Disorders Symptoms of the following disorders can be similar to those of XYY Syndrome. Comparisons may be useful for a differential diagnosis: Klinefelter Syndrome is characterized by the presence of one or more extra x-chromosomes. It affects only males. Individuals with this syndrome tend to be tall and slim in childhood. A striking lack of muscular development, and a small penis and testicles may also occur. Lower than average intelligence, language difficulties, intention tremor, and behavioral problems may be other symptoms. (For more information on this disorder, choose "Klinefelter" as your search term in the Rare Disease Database). Sotos Syndrome is a rare, hereditary disorder characterized by excessive growth during the first 4 to 5 years of life. Other symptoms may include an unusual aggressiveness or irritability, clumsiness and an awkward way of walking. People with this disorder have abnormal patterns of the ridges on the skin of the fingers, palms, toes and soles (dermatoglyphics). Patients have a disproportionately large and long head, with a slightly protrusive forehead, large hands and feet. Mild mental retardation may also occur. (For more information on this disorder, choose "Soto" as your search term in the Rare Disease Database). Marfan Syndrome is an inherited disorder of the connective tissues. People with this disorder tend to be unusually tall and thin with large hands and feet. The face may appear long, and the breastbone may be protruding or indented. They may walk with an irregular or unsteady gait. People with Marfan Syndrome have normal intelligence, and they do not have any behavioral symptoms. (For more information on this disorder, choose "Marfan" as your search term in the Rare Disease Database). Antisocial Personality Disorder is a mental illness characterized in early childhood by behavior such as lying, stealing, fighting, truancy and resisting authority. During adolescence, there may be excessive drinking, use of illicit drugs and aggressive sexual behavior. The behavioral difficulties usually last throughout adult life. In many cases disrespect for authority leads to problems with the law. (For more information on this disorder, choose "Antisocial Personality Disorder" as your search term in the Rare Disease Database). Therapies: Standard Treatment of XYY Syndrome is symptomatic and supportive. Counseling for behavioral or sexual problems may be of benefit. Treatment of acne may help the patient's self-image. Therapies: Investigational Anyone who had a prenatal diagnosis of XYY Syndrome and is between the ages of five and twenty may wish to participate in a study being conducted to determine mental and behavioral outcomes connected with this syndrome. Interested persons may wish to contact Dr. John M. Graham of the UCLA School of Medicine, c/o KS and Associates, P.O. Box 119, Roseville, CA, 95661-0119. This disease entry is based upon medical information available through September 1992. Since NORD's resources are limited, it is not possible to keep every entry in the Rare Disease Database completely current and accurate. Please check with the agencies listed in the Resources section for the most current information about this disorder. Resources For more information on XYY Syndrome, please contact: National Organization for Rare Disorders P.O. Box 8923 New Fairfield, CT 06812-1783 (203) 746-6518 National Mental Health Association 1021 Prince St. Alexandria, VA 22314 (703) 684-7722 National Alliance for the Mentally Ill 1901 N. Fort Meyer Dr., Suite 500 Arlington, VA 22209 (703) 524-7600 National Mental Health Consumer Self-Help Clearinghouse 311 S. Juniper St., Rm. 902 Philadelphia, PA 19107 (215) 735-2481 NIH/National Institute of Mental Health (NIMH) 9000 Rockville Pike Bethesda, MD 20205 (301) 443-4515 or (301) 496-1752 (800) 421-4211 (24 hrs.) International Tremor Foundation 360 W. Superior St. Chicago, IL 60610 (312) 664-2344 For genetic information and genetic counseling referrals, please contact: March of Dimes Birth Defects Foundation 1275 Mamaroneck Avenue White Plains, NY 10605 (914) 428-7100 Alliance of Genetic Support Groups 35 Wisconsin Circle, Suite 440 Chevy Chase, MD 20815 (800) 336-GENE (301) 652-5553 References CECIL TEXTBOOK OF MEDICINE, 18th Ed.: James B. Wyngaarden, and Lloyd H. Smith, Jr., Editors; W.B. Saunders Co., 1988. Pp. 167. INTERNAL MEDICINE, 2nd Ed.: Jay H. Stein, ed.-in-chief; Little, Brown and Co., 1987. Pp. 1989. THE MERCK MANUAL, Volume 1, 15th Ed.: Robert Berkow, M.D., ed.-in-chief; Merck, Sharp, and Dohme Laboratories, 1987. Pp. 2150. SMITH'S RECOGNIZABLE PATTERNS OF HUMAN MALFORMATION, 4th Ed.: Kenneth Lyons Jones, M.D.; W.B. Saunders Co., 1988. Pp. 64-66. EFFECTS OF THE Y CHROMOSOME ON QUANTITATIVE GROWTH: AN ANTHROPOMETRIC STUDY OF 47,XYY MALES. J. Varrela and L. Alvesalo; Am J Phys Anthropol; (Oct 1985; issue 68 (2)). Pp. 239-245. SEX CHROMOSOME ANOMALIES, HORMONES, AND SEXUALITY. R. C. Schiavi, et al.; Arch Gen Psychiatry; (Jan 1988; issue 45 (1)). Pp. 19-24. SEX CHROMOSOME VARIATIONS IN SCHOOL-AGE CHILDREN. F. L. Cohen and J.D. Durham; J Sch Health; (Mar 1985; issue 55 (3)). Pp. 99-102. SPERM CHROMOSOME COMPLEMENTS IN A 47,XYY MAN. J. Benet and R. H. Martin; Hum Genet; (Apr 1988; issue 78 (4)). Pp. 313-315.