$Unique_ID{BRK03738} $Pretitle{} $Title{FG Syndrome} $Subject{FG Syndrome Opitz-Kaveggia Syndrome Townes-Brocks Syndrome VACTERL Association REAR Syndrome} $Volume{} $Log{} Copyright (C) 1991 National Organization for Rare Disorders, Inc. 827: FG Syndrome ** IMPORTANT ** It is possible that the main title of the article (FG 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 Opitz-Kaveggia Syndrome Information on the following disorders can be found in the Related Disorders section of this report: Townes-Brocks Syndrome VACTERL Association REAR Syndrome 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. FG Syndrome is an uncommon hereditary disorder which affects males. The presence and severity of symptoms vary from patient to patient. Some females may have certain physical characteristics related to FG Syndrome because they are "carriers" of the trait, but they are not affected by the disorder itself. Males with FG Syndrome may have mental retardation, an absence of an anal opening (imperforate anus) or an abnormally placed anus, constipation, diminished muscle tone (hypotonia), a large head and certain other physical characteristics. Deafness may be present in some patients. Individuals with FG Syndrome seem to have a specific personality type and are often friendly, outgoing, and hyperactive with a short attention span. Symptoms MALES WITH FG SYNDROME: The presence and severity of symptoms in males with FG Syndrome vary from patient to patient and may include mental retardation, heart defects, delayed muscle system (motor) development, diminished muscle tone (hypotonia), seizures, abnormally large brain (megalencephaly), eyelid abnormalities (short palpebral fissures), constipation, muscle contraction of the joints (multiple joint contractures), webbing of two or more fingers or toes (syndactyly), vertebral defects of the spine, a dimple in the area right above the tailbone (sacral dimple), or undescended testicles (cryptorchidism). The "soft spot" (anterior fontanel) of the baby's skull may be larger than usual. In some patients, there is an absence of an anal opening (imperforate anus). In others, abnormal placement of the anus may occur. The anus may be constricted or smaller than normal (anal stenosis). There may be an abnormal opening located on the underside of the penis (hypospadias). Deafness (sensorineural) is present in some patients and may be severe. Individuals with FG Syndrome are often friendly, and outgoing. They are also hyperactive with a short attention span. They may be easily frustrated and prone to temper tantrums. Physical characteristics can include a disproportionately large head (for height), prominent forehead, cowlick (frontal hair upsweep), unusually wide- set eyes (hypertelorism), a skin fold over the inner corner of the eye (epicanthal folds), prominent lower lip, and small ears. The cornea (of the eye) may appear to be larger than normal. The roof of the mouth (palate) may be narrow, or may have a cleft. Wrinkling of the facial skin is sometimes present. In some individuals, the upper lip is longer than average. Thumbs and big toes are usually broad. Individuals with FG Syndrome often have short stature. Occasionally, skull abnormalities occur such as premature fusion of the unjoined bones of a baby's skull (craniosynostosis), or an accumulation of fluid in the brain (hydrocephalus), or absence of part of the brain known as the corpus callosum. (For more information, choose "hydrocephalus", or "corpus callosum" as your search terms in the Rare Disease Database). Rarely, intestinal abnormalities, heart defects or dilation of the urinary tract may occur. FEMALE "CARRIERS" OF THE FG SYNDROME TRAIT: FG Syndrome is an X-linked trait which is passed from mother to son (see "Causes" section). To date mothers of males with FG Syndrome have shown normal intelligence. Some may have the following physical characteristics: a broad forehead, cowlick, excess skin over the inner corners of the eyes (epicanthal folds), unusually wide-set eyes (hypertelorism), or abnormal placement of the anus. In some females, the upper lip is longer than average. Causes FG Syndrome is inherited as an X-linked recessive trait. Human traits, including the classic hereditary diseases, are the product of the interaction of two genes, one received from the father and one from the mother. X-linked recessive disorders are conditions which are coded on the X chromosome. Females have two X chromosomes, but males have one X chromosome and one Y chromosome. Therefore, in females, disease traits on the X chromosome can be masked by the normal gene on the other X chromosome. Since males only have one X chromosome, if they inherit a gene for a disease present on the X, it will be expressed. Men with X-linked disorders transmit the gene to all their daughters, who are carriers, but never to their sons. Women who are carriers of an X-linked disorder have a fifty percent risk of transmitting the carrier condition to their daughters, and a fifty percent risk of transmitting the disease to their sons. Affected Population FG Syndrome is an uncommon disorder present at birth which affects males. Some females may have certain physical characteristics related to FG Syndrome because they are "carriers" of the trait but they are not affected by the disorder itself. Related Disorders Symptoms of the following disorders can be similar to those of FG Syndrome. Comparisons may be useful for a differential diagnosis: Townes-Brocks Syndrome is a rare genetic disorder present at birth. Characteristics of the disorder and the severity of these symptoms vary from person to person. Major characteristics may include an absence of an anal opening in association with hand, foot and ear abnormalities. Hearing loss or deafness due to lesions or dysfunctions of part of the internal ear or its nerve tracts and centers (sensorineural hearing loss or deafness) is present in some patients. (For more information on this disorder, choose "Townes- Brocks" as your search term in the Rare Disease Database). VACTERL Association is an acronym for (V)ertebral anomalies, (A)nal atresia (absence of a normal anal opening), congenital (C)ardiac disease, (T)racheo(E)sophageal fistula (abnormal openings or passages between the windpipe and/or upper digestive tract), (R)enal anomalies, radial defects, and other (L)imb defects. These abnormalities are present at birth. Symptoms occur in various combinations and can be manifestations of several recognized disorders. (For more information on this disorder, choose "VACTERL" as your search term in the Rare Disease Database). REAR Syndrome is an acronym for (R)enal anomalies, deformed external (E)ars and perceptive deafness, (A)nal stenosis, and (R)adial dysplasia. Underdeveloped kidneys are the most common renal abnormalities. The external ears are abnormally developed and deafness is present at birth. The anus is constricted or smaller than normal and other anal abnormalities can also occur. Abnormal development of the bone in the forearm (radius) or upper arm also occurs. Therapies: Standard Surgery to correct malformations may help individuals with FG Syndrome. Genetic counseling may be of benefit for patients and their families. Other treatment is symptomatic and supportive. Special education services should be helpful for children with this disorder. Therapies: Investigational Scientists are trying to locate the gene on the X chromosome that causes FG Syndrome. When the gene is identified, a prenatal diagnostic and carrier test may be developed for FG Syndrome. This disease entry is based upon medical information available through January 1991. 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 FG Syndrome, please contact: National Organization for Rare Disorders P.O. Box 8923 New Fairfield, CT 06812-1783 (203) 746-6518 FG Syndrome Support Group 66 Ford Road Dagenham, Essex, RM10 9JR England NIH/National Institute of Child Health and Human Development 9000 Rockville Pike Bethesda, MD 20892 (301) 496-5133 Dr. John Opitz Shodair Children's Hospital P.O. Box 5539 Helena, MT 59604 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; Johns Hopkins University Press, 1990. Pp. 1592. SMITH'S RECOGNIZABLE PATTERNS OF HUMAN MALFORMATION, 4th Ed.: Kenneth Lyons Jones, M.D.; W.B. Saunders Co., 1988. Pp. 240-241. FG SYNDROME UPDATE 1988: NOTE OF 5 NEW PATIENTS AND BIBLIOGRAPHY. J. M. Opitz, et al.; Am J Med Genet (May-Jun 1988; issue 30 (1-2)). Pp. 309-328. SENSORINEURAL DEAFNESS IN THE FG SYNDROME: REPORT ON FOUR NEW CASES. G. Neri, et al.; Am J Med Genet (Oct 1984; issue 19 (2)). Pp. 369-377. THE FG SYNDROME: FURTHER CHARACTERIZATION, REPORT OF A THIRD FAMILY, AND OF A SPORADIC CASE. V. M. Riccardi, et al.; Am J Med Genet (1977; issue 1 (1)). Pp. 47-58. THE FG SYNDROME: 7 NEW CASES. E. M. Thompson, et al.; Clin Genet (Jun 1985; issue 27 (6)). Pp. 582-594.