Smith-Magenis syndrome (SMS) is a distinct and clinically recognizable genetic disorder characterized by a specific pattern of physical, behavioral, and developmental features. SMS, which was first described in the early 1980's by Ann C.M. Smith, MA (a genetic counselor) and Ellen Magenis, MD (a cutogeneticist), is the result of a deletion of chromosome 17 (17p11.2). The chromosomal deletion occurs from a spontaneous genetic change (mutation) that happens for unknown reasons, therefore, it is not a familial disorder. SMS is considered a rare disorder and is estimated to occur in 1 out of every 25,000 live births. Currently there are over 100 cases reported, however, it is believed that SMS is widely underdiagnosed because clinical features may be subtle. It is expected that with increased awareness, the number of those identified as having SMS will increase.
Features and Characteristics
There are many characteristics associated with SMS. Not every individual has all the characteristics, however, the following is a list of traits that have been reported:
- Distinct facial features: brachycephaly (short wide head), mid-face hypoplasia, prominent forehead, epicanthal folds, broad nasal bridge, prognathism (protruding jaw), and ear anomalies
- Brachydactyly (short fingers and toes)
- Short stature
- Hoarse, deep voice
- Speech delay
- Learning disability
- Mental retardation (varying degrees, but have IQs typically in the 50-60 range)
- Low muscle tone and/or feeding problems in infancy
- Eye problems
- Sleep disturbances
- Insensitivity to pain
- Behavioral problems: hyperactivity; head banging; hand/nail biting; skin picking; pulling off fingernails and/or toenails; explosive outbursts; tantrums; destructive and aggressive behavior; excitability; arm hugging/hand squeezing when excited
- Engaging and endearing personalities
Less common symptoms include:
- Heart defects
- Urinary tract abnormalities
- Abnormalities of the palate, cleft lip
- Hearing impairment
The diagnosis of SMS is usually confirmed through a blood test (called a high resolution chromosome analysis), which is typically performed for the evaluation of developmental delay and/or congenital anomalies. However, in the older child, the phenotype is distinctive enough for a clinical diagnosis to be made by an experienced clinician prior to the chromosome analysis.
Treatment / What to Expect
There is no cure for SMS, therefore, the treatment program involves managing the childs symptoms. The child with SMS typically displays self-injurious behavior at home and in the classroom. There are also problems with attention-seeking outbursts and aggressive behavior. For some, medication may be given to try to control some of the behaviors although, in most cases, medications arent particularly helpful.
In addition to behavioral problems, children with SMS tend to have speech delays. Therefore, speech therapy, starting very early on, is typically beneficial. Most will learn to communicate verbally, with sign language, and/or gestures.
Since children with SMS are often easily distracted, they tend to do better in smaller, calmer, and more focused classroom settings, where there are no more than five to seven children with one teacher and one aide. Should the class be any larger than this, the competition for the teachers attention increases, as does the possibility of behavioral problems. They also seem to respond positively to consistency, structure, and routines; changes in routine can provoke behavioral outbursts and tantrums. Children with SMS have difficulty in sequential processing, which makes counting, mathematical tasks, and multi-step tasks difficult. They tend to learn best with visual cues (pictures illustrating tasks, schedules, etc.). Also, since they have a fascination with electronics, the use of assistive technology may be a good tool for teaching. Children with SMS are generally very responsive to affection, praise, and other positive emotions on the part of the teacher and enjoy interaction with adults. A teachers positive response can often motivate a child to do well.
More than half of children with SMS have sleep disturbances, therefore, it is recommended that their room be set up so that the child is not in any danger. This may mean removing small items or other objects that can be harmful to the child and using a locking mechanism on the door so that the child cannot leave his room to wander the house.
Ariel came to be part of our family in 1985 at the age of 12 weeks. Although we had gone through the process of a "Special Needs" adoption, her dad and I steadfastly ignored the implications of her delayed development and feeding disturbances, focusing instead on the placid nature of our 3rd child. As she left toddlerhood, we could no longer ignore her complete lack of sound production and the large bruises she had raised on her forehead from banging on the hardest surface she could find at any given moment.
Ariel's pre-school and early elementary years were fraught with screaming during daylight hours, rampaging the house and hoarding food by night and pulling out fingernails and toenails whenever she was unattended. Her frequent fits were contrasted by her impromptu sleeps which could happen on a neighbor's porch, in school or (heaven help us) on a float in the pool!
In her pre-teen and early teen years, Ariel's picture became even more desperate due to profound health problems (resulting from intestinal pseudo-obstruction, not SMS). Difficult, but necessary, medical procedures were even more nightmarish when undertaken in a child with Smith-Magenis syndrome.
Ariel will be 15 on March 8. Two years ago she celebrated her Bat Mitzvah and her father and I experienced a pinnacle of pride we have yet to equal. She still screams a lot. When she is "bored" she pulls out her nails. Our kitchen and family room are padlocked throughout the night. We no longer despair about her present or her future and we reflect on her past with amazement. As the past several years unfolded, we were able to develop a collaborative network of compassionate, knowledgeable physicians, arrive at a classroom placement with a veteran talented educator, maintain a support structure of dedicated, diligent respite providers and behavior consultants and throng Ariel with a circle of friends from our synagogue and her high school. It has taken, not a village, but a virtual metropolis to nurture and raise Ariel. Yet, all who have participated have been rewarded at various junctures in the experience and we all look forward to Ariel's adulthood with cautious, but well placed, optimism. - Laurie Bellet
Kristin was born with low muscle tone and had problems coordinating her breathing and sucking, therefore, I had difficulty nursing her and had to discontinue much earlier than I did for her siblings. Kristin walked at about 2 years of age. She had numerous ear infections as an infant and toddler, but she started to have fewer and fewer as she got older. She has had tubes put in her ears 5 times. When she was an infant and toddler, she drooled a lot and always seemed to be stuffed up. She is non-verbal, but can hear. She uses American Sign Language to communicate, and started learning to sign at about 13 months of age. Her first signed word was "more." She does have a mild hearing loss, wears glasses for reading, and wore orthodic braces on her feet until she was about 6 years old. Kristin has difficulty with gross and fine motor skills.
Kristin, like many SMS children, has a lot of attention seeking behaviors. She loves to be around adults and gets upset when anyone has my attention, although, as she gets older, we see this diminishing. I think it also has to do with the fact that I have laid down the law that if someone needs my help or wants to talk to me, she has to wait. I also try to redirect her with a fun activity. She used to have a lot of self-injurious behavior; banging her head on the wall, cement, floor, etc., but this is diminishing as she gets older. She gets very frustrated trying to communicate with people who don't understand what she is signing.
Kristin has negative reactions to changes in routine. If there is an assembly at school, and we aren't notified so I can tell her ahead of time, she gets upset because that throws her routine off. She can remember the finest details of things. For example, if someone were to come to our house with blue glasses and the next time she saw them they had on blue glasses but maybe a little bit different shade (one that you or I would never pick up on), she would immediately notice that and ask the person about it. She doesn't seem to have a concept of time... tomorrow, in one hour, on Friday, etc.
The biggest problem is sleep disturbance - the number one complaint of parents of children with SMS. We had to turn the lock around on her bedroom door so she doesn't get out of her room and wander out of the house at night. A lot of SMS parents have had to do this. Children with SMS have melatonin levels that are opposite of ours. Our levels begin to increase at about 9 p.m., peak at midnight, and decrease until dawn. SMS children have levels that begin to rise in the morning and peak at noon. Therefore, children with SMS (Kristin has done this many times) will even fall asleep while eating dinner. One minute she will have energy and be eating like the rest of us and then all of a sudden, shell start to fall asleep with food in her mouth. She gets tired a lot during the day, which makes sense considering the melatonin levels.
One of the best things about Kristin is her loving, outgoing personality. In fact, we're trying to teach her not to be so affectionate, for obvious reasons. She needs to realize that she just can't go up to complete strangers and hug them if they act like they like her. She has taught us a lot about compassion and patience. Kristin's siblings have learned a lot about compassion and are sensitive to other people's feelings.
One thing that we are cognizant of is to make sure we spend time with Kristin's other siblings. We try to make special time for each child, although there are days that go by that we don't do it as much as we should have. One important thing for parents of special siblings to remember, and I have to keep reminding myself, is to spend time with the typical children so there isn't a feeling of resentment. We will be going to a conference on SMS, and this time, we plan on taking Kristin's older sister with us. Just the three of us will attend. Previously, we did not take Kristin's older sibling.
Some final thoughts: Kristin is eager to please, is motivated by a number of things (Barney stuff, books - she loves books, a trip to McDonald's, stickers, etc.), she has a great sense of humor, and loves the computer. She is presently in a third grade inclusion class. - Ginny Slobe
If you are interested in meeting other parents and individuals who are involved in raising a child with Smith-Magenis syndrome, the following listserv is available:
SMS List - To subscribe, click here: http://www.egroups.com/list/sms-list/info.html
For more information on Smith-Magenis syndrome, please see the following references:
- The National Human Genome Research Institute http://www.nhgri.nih.gov/DIR/MGB/SMS97/about_sms.html
- University of Kansas Medical Center http://www.kumc.edu/gec/support/smith-ma.html
- National Organization for Rare Disorders http://www.stepstn.com/cgi-win/nord.exe?proc=Redirect&type=rdb_sum&id=976.htm
- Online Mendelian Inheritance in Man http://www3.ncbi.nlm.nih.gov/htbin-post/Omim/dispmim?182290
- Baylor College of Medicine http://www.imgen.bcm.tmc.edu/molgen/lupski/sms/Index-SMS.htm
The Disorder Zone has been created for educational purposes only and is not intended to serve as medical advice. The information provided in The Zone should not be used for diagnosing or treating a health problem or disease. It is not a substitute for professional care. If your child has any health concerns, please consult your health care provider.
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