Post by momofautistic on Jul 4, 2004 13:40:05 GMT -5
What is Smith-Magenis Syndrome?
A syndrome is a recognizable pattern of physical, behavioral, and developmental features which occur together in the same person due to a single, underlying cause. Smith-Magenis syndrome (SMS) is associated with a small, missing section (called a deletion) of chromosome 17. The first group of children with this deletion was described in the 1980's by Ann C.M. Smith, a Jj genetic counselor, and Ellen Magenis, a physician and chromosome expert. The diagnosis of SMS is usually confirmed through blood tests called chromosome (cytogenetic) analysis and FISH (fluorescence in situ hybridization). Most people with the diagnosis have been identified since 1995 as a result of improved laboratory techniques which allow the accurate detection of this chromosomal deletion. Although the exact incidence is not known, it is estimated that SMS occurs in 1 out of 25,000 births. SMS is under-diagnosed, but as awareness of it increases, the number of people identified grows every year.
CHARACTERISTICS OF SMS
A variety of unusual physical and behavioral characteristics have been found in people with SMS. An individual with SMS may have just a few or many of the features listed below: Physical Features
short stature; characteristic facial appearance (flattened mid-face, down-turned mouth, prominent and often rosy cheeks; prominent jaw in older children and adults. (Note: these facial characteristics can be subtle.); chronic ear infections; hearing impairment; eye problems, including: strabismus (an eye which turns in or out) and myopia (nearsightedness); hoarse voice; short fingers and toes; heart defects / murmurs; problems related to the urinary system; scoliosis (curvature of the spine); an unusual gait (walking pattern); decreased sensitivity to pain Characteristics During Infancy "cherubic" facial appearance; happy disposition; infrequent crying; low muscle tone; feeding problems Sleep problems frequent awakenings increased daytime naps Behavioral and developmental characteristics
speech delay and articulation problems; developmental delay; learning disability; mental retardation; hyperactivity; self-injury, including: head banging; hand biting; picking at skin, sores and nails; pulling off finger- and toenails; inserting foreign objects into ears, nose, or other body orifices; explosive outbursts; prolonged tantrums; destructive and aggressive behavior; excitability; arm hugging / hand squeezing when excited
Some people with SMS may never show significant behavioral problems, although some degree of self-injury and sleep disturbance occurs in most. Despite their very difficult behaviors, children and adults with SMS are very
appealing and affectionate, and have much untapped potential. EARLY INTERVENTION While there is no medical prevention or cure, early diagnosis of SMS gives parents time to learn about and prepare for the challenges that lie ahead. Knowing the cause of their child's developmental delays can facilitate a family's access to important early intervention services and may help program staff identify areas of specific need or risk. Additionally, a diagnosis of SMS opens the doors to a network of information and support from professionals and other families dealing with the syndrome.
GENETICS
Although SMS is caused by a deletion of genetic material, it usually does not run in families. In most cases, the deletion occurs accidentally in a child around the time he or she is conceived, without being inherited from either parent. For this reason, we can say that SMS is clearly genetic, but not usually familial. Families are advised to consult a genetics specialist for further advise regarding their own particular family situation.
A syndrome is a recognizable pattern of physical, behavioral, and developmental features which occur together in the same person due to a single, underlying cause. Smith-Magenis syndrome (SMS) is associated with a small, missing section (called a deletion) of chromosome 17. The first group of children with this deletion was described in the 1980's by Ann C.M. Smith, a Jj genetic counselor, and Ellen Magenis, a physician and chromosome expert. The diagnosis of SMS is usually confirmed through blood tests called chromosome (cytogenetic) analysis and FISH (fluorescence in situ hybridization). Most people with the diagnosis have been identified since 1995 as a result of improved laboratory techniques which allow the accurate detection of this chromosomal deletion. Although the exact incidence is not known, it is estimated that SMS occurs in 1 out of 25,000 births. SMS is under-diagnosed, but as awareness of it increases, the number of people identified grows every year.
CHARACTERISTICS OF SMS
A variety of unusual physical and behavioral characteristics have been found in people with SMS. An individual with SMS may have just a few or many of the features listed below: Physical Features
short stature; characteristic facial appearance (flattened mid-face, down-turned mouth, prominent and often rosy cheeks; prominent jaw in older children and adults. (Note: these facial characteristics can be subtle.); chronic ear infections; hearing impairment; eye problems, including: strabismus (an eye which turns in or out) and myopia (nearsightedness); hoarse voice; short fingers and toes; heart defects / murmurs; problems related to the urinary system; scoliosis (curvature of the spine); an unusual gait (walking pattern); decreased sensitivity to pain Characteristics During Infancy "cherubic" facial appearance; happy disposition; infrequent crying; low muscle tone; feeding problems Sleep problems frequent awakenings increased daytime naps Behavioral and developmental characteristics
speech delay and articulation problems; developmental delay; learning disability; mental retardation; hyperactivity; self-injury, including: head banging; hand biting; picking at skin, sores and nails; pulling off finger- and toenails; inserting foreign objects into ears, nose, or other body orifices; explosive outbursts; prolonged tantrums; destructive and aggressive behavior; excitability; arm hugging / hand squeezing when excited
Some people with SMS may never show significant behavioral problems, although some degree of self-injury and sleep disturbance occurs in most. Despite their very difficult behaviors, children and adults with SMS are very
appealing and affectionate, and have much untapped potential. EARLY INTERVENTION While there is no medical prevention or cure, early diagnosis of SMS gives parents time to learn about and prepare for the challenges that lie ahead. Knowing the cause of their child's developmental delays can facilitate a family's access to important early intervention services and may help program staff identify areas of specific need or risk. Additionally, a diagnosis of SMS opens the doors to a network of information and support from professionals and other families dealing with the syndrome.
GENETICS
Although SMS is caused by a deletion of genetic material, it usually does not run in families. In most cases, the deletion occurs accidentally in a child around the time he or she is conceived, without being inherited from either parent. For this reason, we can say that SMS is clearly genetic, but not usually familial. Families are advised to consult a genetics specialist for further advise regarding their own particular family situation.
