A syndrome is a recognizable pattern of physical, behavioral, and developmental
features that occur together in the same person due to a single, underlying
cause. Smith-Magenis syndrome (or SMS) is a chromosomal disorder characterized
by a recognizable pattern of physical, behavioral, and developmental features.
It is caused by a missing piece of genetic material from chromosome 17, referred
to as deletion 17p11.2.
Common features include: characteristic, yet subtle, facial appearance, infant
feeding problems, low muscle tone, developmental delay, variable levels of mental
retardation, early speech/language delay, middle ear problems, skeletal anomalies
and decreased sensitivity to pain. The syndrome also includes a distinct pattern
of neurobehavioral features characterized by chronic sleep disturbances, arm
hugging/hand squeezing, hyperactivity and attention problems, prolonged tantrums,
sudden mood changes and/or explosive outbursts and self-injurious behaviors.
For a more complete list of physical, developmental and behavioral characteristics,
please click here
.
Ann
C.M. Smith, M.A., D.Sc. (hon) a genetic counselor, and Dr. R. Ellen Magenis, a
physician and chromosome expert, described the first group of children with
this deletion in the 1980's. Most people with the diagnosis have been identified
since 1995 as a result of improved laboratory techniques that 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.
Spotlight On
Morgan
by
Cassie Jones and Darrin Hulse
Morgan was born on
Jan. 24th, 2001. She was a beautiful baby and ... >> read more