$Unique_ID{BRK03601} $Pretitle{} $Title{Chromosome 6 Ring} $Subject{Chromosome 6 Ring Ring 6 Ring 6 Chromosome Chromosomal Disorders} $Volume{} $Log{} Copyright (C) 1992 National Organization for Rare Disorders, Inc. 928: Chromosome 6 Ring ** IMPORTANT ** It is possible that the main title of the article (Chromosome 6 Ring) is not the name you expected. Please check the SYNONYMS listing to find the alternate name and disorder subdivisions covered by this article. Synonyms Ring 6 Ring 6, Chromosome Information on the following diseases can be found in the Related Disorders section of this report: Chromosomal Disorders 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. Chromosome 6 Ring is a rare chromosomal disorder in which the patient has a breakage of chromosome 6 at both ends, and the ends of the chromosome join together to form a ring. The amount of genetic material lost at the two ends of the chromosome can vary. As a result, a patient with very little absent genetic material may have no apparent symptoms while a patient with a significant part of the chromosomal ends missing may have many symptoms. The most apparent features of this disorder are mild to severe mental retardation, delays in growth and self-controlled muscle movement (psychomotor retardation), a small head circumference and jaw, low-set ears, a flat nasal bridge, and/or abnormalities of the eyes. Symptoms Chromosome 6 Ring is a very rare chromosomal disorder in which the symptoms depend on the amount of genetic material lost on the small and long arms (ends) of the sixth chromosome. As a result, patients symptoms can vary. Patients with very little missing genetic material may have no apparent symptoms while patients with a significant amount of material missing from the chromosome ends may have many symptoms. The features seen most often in patients with Chromosome 6 Ring are mild to severe mental retardation, delays in growth and self-controlled muscle movement (psychomotor retardation), a small head circumference and jaw, low- set ears, a flat nasal bridge and/or abnormalities of the eyes. Other symptoms that have been found in some patients with Chromosome 6 Ring may be: widely spaced eyes, a vertical fold of skin over the inner corner of the eye (epicanthal folds), a high-arched palate, club foot, fluid on the brain causing enlargement of the head (hydrocephalus), webbed skin, a short neck, downward slanting eyes, and/or widely spaced nipples. Causes Chromosome 6 Ring is a very rare chromosomal disorder caused by a deletion of chromosome 6 at both ends and a joining of the ends to form a ring. The genetic material lost from the ends can vary from a small amount causing few symptoms to a significant amount causing many symptoms. There is no apparent reason why this occurs. Most chromosomal deletions occur "de novo" which means that they occur very early in the development of the embryo for no apparent reason. The parents of the affected child typically have normal chromosomes and a very low possibility of having another child with a chromosomal abnormality. Affected Population Chromosome 6 Ring is a very rare chromosomal disorder that affects males slightly more often than females. There have been approximately 17 cases of this disorder reported in the medical literature. Related Disorders Many chromosomal disorders involving mental retardation have some features similar to Chromosome 6 Ring. The only way to determine which chromosomal disorder a patient has is through genetic testing. (For more information choose "retardation" as your search term in the Rare Disease Database). Therapies: Standard Patients with Chromosome 6 Ring and poor muscle tone may benefit from physical therapy. Special education and related services will be of benefit to children with this disorder. Genetic counseling may be of benefit for patients and their families. Other treatment is symptomatic and supportive. Therapies: Investigational Research on birth defects and their causes is ongoing. The National Institutes of Health (NIH) is sponsoring the Human Genome Project which is aimed at mapping every gene in the human body and learning why they sometimes malfunction. It is hoped that this new knowledge will lead to prevention and treatment of genetic disorders in the future. 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 Chromosome Ring 6, please contact: National Organization for Rare Disorders (NORD) P.O. Box 8923 New Fairfield, CT 06812-1783 (203) 746-6518 Chromosome Deletion Outreach P.O. Box 164 Holtsville, NY 11742 (516) 736-6754 Association for Retarded Citizens of the U.S. P.O. Box 6109 Arlington, TX 76005 (817) 640-0204 (800) 433-0525 NIH/National Institute of Child Health and Human Development 9000 Rockville Pike Bethesda, MD 20892 (301) 496-5133 For Genetic Information and Genetic Counseling Referrals: 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 BIRTH DEFECTS ENCYCLOPEDIA, Mary Louise Buyse, M.D., Editor-In-Chief; Blackwell Scientific Publications, 1990. Pp. 343. RING CHROMOSOME 6: CLINICAL AND CYTOGENETIC BEHAVIOR: C. Paz-y-Mino et al.; Am J Med Genet (April 1990, issue 35(4)). Pp. 481-3. RING CHROMOSOME 6: REPORT OF A PATIENT AND LITERATURE REVIEW: D. Chitayat et al.; Am J Med Genet (January, 1987, issue 35(4)). Pp. 145-51.