$Unique_ID{BRK03973} $Pretitle{} $Title{Marshall-Smith Syndrome} $Subject{Marshall-Smith Syndrome MSS Weaver Syndrome Gigantism Sotos Syndrome McCune-Albright Syndrome } $Volume{} $Log{} Copyright (C) 1990 National Organization for Rare Disorders, Inc. 820: Marshall-Smith Syndrome ** IMPORTANT ** It is possible that the main title of the article (Marshall-Smith 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 MSS Information on the following disorders can be found in the Related Disorders section of this report: Weaver Syndrome Gigantism Sotos Syndrome McCune-Albright 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. Marshall-Smith Syndrome is characterized by unusually quick physical growth and bone development (maturation), usually starting before birth. Other symptoms can include respiratory difficulties, mental retardation, and certain physical characteristics. (Note: Marshall-Smith Syndrome is not to be confused with "Marshall" Syndrome, which is very different from "Marshall- Smith" Syndrome). Symptoms In patients with Marshall-Smith Syndrome growth and bone development (maturation) occur faster than normal. The individual is underweight in relation to his or her height and does not thrive well. Other symptoms include diminished muscle tone (hypotonia), muscle weakness, hernias in the abdomen (umbilical hernias), and/or mental retardation. Slow development of voluntary movements (psychomotor retardation) may also occur. Breathing (respiratory) difficulties commonly occur in patients with Marshall-Smith Syndrome. High-pitched noisy breathing which sounds similar to the wind blowing (stridor), extension of the neck beyond normal limits (hyperextension), or the tongue obstructing the air passage may occur. Physical characteristics of Marshall-Smith Syndrome include excessive hair growth (hypertrichosis), a long head with a prominent forehead, prominent eyes, and/or an upturned nose with a low nasal bridge. The white of the eye (sclerae) may appear bluish. The angle of the lower jawbone on each side of the face as it joins in the front to form the chin (mandibular ramus) may be smaller than average. Generally, the bones of the fingertips (distal phalanges) are narrow but the rest of the bones in the fingers (proximal and middle phalanges) are broad. Infrequently, the leaf-shaped structure in the throat which normally prevents food or liquid from passing into the windpipe (epiglottis) may not develop properly in some patients with Marshall-Smith Syndrome. Absent and/or smaller than normal openings leading from the nasal passages into the post-nasal space (choanal atresia and/or stenosis), an abnormal larynx and/or soft cartilage of the larynx (laryngomalacia), a short breastbone (sternum), or a deep crease between the big toe (hallux) and second toe may occur in some patients. Occasionally, brain abnormalities such as atrophy (cerebral atrophy), larger than normal convolutions of the cerebral cortex (macrogyria), or an absent corpus collosum may occur. (For more information on absence of the corpus collosum, choose "corpus collosum" as your search term in the Rare Disease Database). Defects in the immune system (immunologic defect) are sometimes present. Although rare, some babies with Marshall-Smith Syndrome are born with a sac containing part of the intestines protruding outside the abdominal wall, with the umbilical cord attached (omphalocele). Causes The exact cause of Marshall-Smith Syndrome is unknown. There is no evidence that it is genetic. Affected Population Marshall-Smith Syndrome is a rare disorder present at birth affecting males and females in equal numbers. Symptoms of the syndrome are usually present before birth (prenatal onset). Related Disorders Weaver Syndrome is similar to Marshall-Smith Syndrome in that growth and bone maturation occur faster than normal. However, patients with Weaver Syndrome have normal to above normal weight in relation to their height whereas patients with Marshall-Smith Syndrome are underweight in relation to their height. There are other differences as well. For example, Marshall-Smith Syndrome patients have different physical characteristics, respiratory difficulties, and other symptoms that patients with Weaver Syndrome do not have. (For more information on Weaver Syndrome, choose "Weaver" as your search term in the Rare Disease Database). Gigantism occurs before puberty and is caused by oversecretion of growth hormone. It is characterized by excessive growth during childhood with relatively normal body proportions and sexual development. Height sometimes reaches 7 or 8 feet. Soft tissues are also enlarged. In extreme cases, disease of muscle tissue (myopathy) and abnormalities of nerves distant from the brain and spinal cord (peripheral neuropathy) may occur. Certain hereditary syndromes such as Klinefelter Syndrome, Marfan Syndrome, and some of the lipodystrophies, may include tallness among their symptoms. (For more information choose "gigantism, ""giant," or "peripheral neuropathy" as your search term in the Rare Disease Database). Soto's Syndrome is a rare, hereditary disorder characterized by excessive growth (over the 90th percentile) during the first 4 to 5 years of life. Abnormalities of the nervous system, including aggressiveness, irritability, clumsiness, an awkward gait, and mental retardation sometimes also occur. Physical characteristics also include eyes which appear to be abnormally far apart (hypertelorism) and slanted. (For more information, choose "Soto" as your search term in the Rare Disease Database.) McCune-Albright Syndrome (Osteitis Fibrosa Disseminata) is characterized by an early (precocious) sexual development, a change in bone integrity which produces pain, increasing deformity and disability, and possible changes in skin pigmentation. This syndrome involves the endocrine, muscle and bone systems. Excessive secretion of growth hormone as well as other hormones occurs in some cases. Children with McCune-Albright Syndrome are excessively tall during childhood, but their growth stops early and they usually don't reach normal height during adulthood. (For more information, choose "McCune-Albright" as your search term in the Rare Disease Database.) Therapies: Standard Treatment of Marshall-Smith Syndrome is symptomatic and supportive. Aggressive treatment of breathing (respiratory) difficulties is necessary. Special education and related services will be necessary during school years. Therapies: Investigational 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 Marshall-Smith Syndrome, please contact: National Organization for Rare Disorders P.O. Box 8923 New Fairfield, CT 06812-1783 (203) 746-6518 The Magic Foundation 1327 N. Harlem Ave. Oak Park, IL 60302 (708) 383-0808 Human Growth Foundation (HGF) 7777 Leesburg Pike P.O. Box 3090 Falls Church, VA 22043 (703) 883-1773 (800) 451-6434 NIH/National Institute of Child Health and Human Development 9000 Rockville Pike Bethesda, MD 20892 (301) 496-5133 Alliance of Genetic Support Groups 35 Wisconsin Circle, Suite 440 Chevy Chase, MD 20815 (800) 336-GENE (301) 652-5553 References SMITH'S RECOGNIZABLE PATTERNS OF HUMAN MALFORMATION, 4th Ed.: Kenneth Lyons Jones, M.D.; W.B. Saunders Co., 1988. Pp. 134-135. MARSHALL-SMITH SYNDROME: NEW ASPECTS. A. M. Roodhooft, et al.; Neuropediatrics (Nov 1988; issue 19 (4)). Pp. 179-182. MARSHALL-SMITH SYNDROME: TWO CASE REPORTS AND A REVIEW OF PULMONARY MANIFESTATIONS. J. P. Johnson, et al.; Pediatrics (Feb 1983; issue 71 (2)). Pp. 219-223. THE SYNDROMES OF MARSHALL AND WEAVER. N. Fitch; J Med Genet (Jun 1980; issue 17 (3)). Pp. 174-178.