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$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.