$Unique_ID{BRK03552} $Pretitle{} $Title{C Syndrome} $Subject{C Syndrome Opitz Trigonocephaly Syndrome Trigonocephaly "C" Syndrome Trigonocephaly Syndrome Trigonocephaly (autosomal dominant type) Trigonocephaly (autosomal recessive) Trigonocephaly with Short Stature and Developmental Delay} $Volume{} $Log{} Copyright (C) 1992 National Organization for Rare Disorders, Inc. 917: C Syndrome ** IMPORTANT ** It is possible that the main title of the article (C Syndrome) is not the name you expected. PLease check the SYNONYMS listing to find the alternate name and disorder subdivisions covered by this article. Synonyms Opitz Trigonocephaly Syndrome Trigonocephaly "C" Syndrome Trigonocephaly Syndrome Information on the following diseases can be found in the Related Disorders section of this report: Trigonocephaly (autosomal dominant type) Trigonocephaly (autosomal recessive) Trigonocephaly with Short Stature and Developmental Delay 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. C Syndrome is a rare disorder thought to be inherited as an autosomal recessive trait. Patients with this disorder are born with a malformation in which the head is a triangular shape due to premature union of the skull bones (trigonocephaly), a narrow pointed forehead, a flat broad nasal bridge with a short nose, vertical folds over the inner corner of the eye, an abnormal palate that is deeply furrowed, abnormalities of the ear, crossed eyes (strabismus), joints that are bent or in a fixed position, and loose skin. All recorded patients except one have had mental retardation. Symptoms One of the distinguishing features of C syndrome is a condition in which the skull is a triangular shape primarily due to premature closure of the bones (trigonocephaly). Patients with this disorder also have a distinct face in which the nasal bridge is broad with a short nose, and there are vertical folds over the inner corners of the eyes (epicanthus). A deeply furrowed palate in the mouth, abnormalities of the outer ear, crossed eyes (strabismus), joints that may be bent in a fixed position or dislocated, and loose skin are all features typically found in patients with C Syndrome. Epicanthus, retardation, loss of muscle tone, abnormalities of the sternum, facial palsy, webbed fingers and/or toes, short limbs, heart defects, failure of one or both testicles to move down into the scrotum (cryptorchidism), abnormalities of the kidneys and lungs, deformity of the lower jaw and/or seizures may also be found in patients with C Syndrome. Causes C Syndrome is thought to be inherited as an autosomal recessive trait. Human traits, including the classic genetic diseases, are the product of the interaction of two genes, one received from the father and one from the mother. In recessive disorders, the condition does not appear unless a person inherits the same defective gene for the same trait from each parent. If one receives one normal gene and one gene for the disease, the person will be a carrier for the disease, but usually will not show symptoms. The risk of transmitting the disease to the children of a couple, both of whom are carriers for a recessive disorder, is twenty-five percent. Fifty percent of their children will be carriers, but healthy as described above. Twenty-five percent of their children will receive both normal genes, one from each parent, and will be genetically normal. Affected Population C Syndrome is a very rare disorder that affects males and females in equal numbers. There have been approximately twenty-five cases reported in the medical literature. Related Disorders Symptoms of the following disorders can be similar to those of C Syndrome. Comparisons may be useful for a differential diagnosis: Trigonocephaly (autosomal dominant type) is a rare disorder inherited as an autosomal dominant trait. Patients with this disorder are born with a triangular shaped skull partially caused by premature closure of the bones which can cause compression of the brain. A small head and skin tags on the ears have been found in several cases. Mental development is normal in all cases. This disorder affects males five times more often than females. There have been six patients from one family reported in the medical literature. Trigonocephaly (autosomal recessive) is a rare disorder that is inherited as an autosomal recessive trait. Patients with this disorder are born without the nerve fibers that are related to the sense of smell, as well as a malformation in which the skull is a triangular shape partially caused by premature closure of the bones (trigonocephaly). There have been multiple affected siblings reported in the medical literature. Trigonocephaly with Short Stature and Developmental Delay is a rare disorder inherited as an X-Linked trait. This disorder has been characterized by a malformation in which the skull is a triangular shape partially caused by premature closure of the bones of the skull (trigonocephaly), short stature and moderate mental retardation in three males recorded in the medical literature. The other two related patients had a closed space between the bones at the back of the skull, a narrow forehead, widely spaced eyes, a small head circumference, low weight, and slow mental and physical development. Typically the borders or joints of the skull close between the ages of 28 and 32 years. Patients with Trigonocephaly with Short Stature and Developmental Delay have closure between the ages of 2 and 3 years. There have been five related patients described in the medical literature and all were males. Therapies: Standard When Trigonocephaly is severe surgery may be performed to relieve the pressure on the brain and cosmetically improve facial appearance. Other treatment is symptomatic and supportive. Genetic counseling may be of benefit for patients and their families. 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 May 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 C Syndrome, please contact: National Organization for Rare Disorders (NORD) P.O. Box 8923 New Fairfield, CT 06812-1783 (203) 746-6518 National Craniofacial Foundation 3100 Carlisle St., Suite 215 Dallas, TX 75204 (800) 535-3643 FACES National Association for the Craniofacially Handicapped P.O. Box 11082 Chattanooga, TN 37401 (615) 266-1632 NIH/Niational 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 MENDELIAN INHERITANCE IN MAN, 9th Ed.: Victor A. McKusick, Editor: Johns Hopkins University Press, 1990. Pp. 943, 1072-3, 1515, and 1731. BIRTH DEFECTS ENCYCLOPEDIA, Mary Louise Buyse, M.D., Editor-In-Chief; Blackwell Scientific Publications, 1990. Pp. 251-52. MODIFICATION IN THE SURGICAL CORRECTION OF TRIGONOCEPHALY: A.M. Sadove, et al.; Plast Reconstr Surg (June, 1990, issue 85(6)). Pp. 853-8. "C" TRIGONOCEPHALY SYNDROME: CLINICAL VARIABILITY AND POSSIBILITY OF SURGICAL TREATMENT: F. Lalatta, et al.; Am J Med Genet (December, 1990, issue 37(4)). Pp. 451-6.