SMS Medical Management Guidelines

These guidelines were developed and approved by PRISMS Professional Advisory Board. They are published as part of the in-depth review of SMS that appears in GeneReviews.

Management involves evaluation for manifestations of SMS and treatment to mitigate symptoms.

Evaluations. At the time of diagnosis of SMS, a series of baseline evaluations are recommended to guide medical management, including the following:

  • Complete review of systems at the time of diagnosis
  • Physical and neurological examination
  • Renal ultrasound examination to evaluate for possible renal/urologic anomalies (~20% of individuals with SMS)
  • Echocardiogram to evaluate for possible cardiac anomalies (<45% of individuals with SMS); follow-up depending upon the severity of any cardiac anomaly identified
  • Spine radiographs to evaluate for possible vertebral anomalies and scoliosis (~60%)
  • Routine blood chemistries, qualitative immunoglobulins, fasting lipid profile, and thyroid function studies
  • Ophthalmologic evaluation with careful attention to evidence of strabismus, microcornea, iris anomalies and refractive error. Treatment with corrective lenses as indicated.
  • Comprehensive speech/language pathology evaluation, with special emphasis during early childhood
  • Assessment of caloric intake, signs and symptoms of gastroesophageal reflux (GER), swallowing abilities and oral motor skills with referral as warranted for full diagnostic evaluation
  • Otolaryngologic evaluation to assess ear, nose, and throat problems, with specific attention to ear physiology and palatal abnormalities (clefting; velopharyngeal insufficiency). Recurrent otitis media may require treatment with tympanostomy tubes.
  • Audiologic evaluation at regular intervals to monitor for conductive and/or sensorineural hearing loss. Amplification may be required.
  • Multidisciplinary developmental evaluation, including assessment of motor, speech, language, personal-social, general cognitive, and vocational skills
  • Early evaluation by physical and/or occupational therapists and implementation of services as needed
  • Sleep history with particular attention to sleep/wake schedules and respiratory function. Sleep diaries may prove helpful in documenting sleep/wake schedules. Evidence of sleep-disordered breathing warrants polysomnogram and overnight sleep study to evaluate for obstructive sleep apnea.
  • Assessment of family support and psychosocial and emotional needs to assist in designing family interventions
  • Parental chromosome analysis to permit accurate recurrence risks and provision of genetic counseling

Recommended annually:

  • Multidisciplinary team evaluation is optimal, including physical, occupational and speech therapy evaluations, and pediatric assessment to assist in development of Individualized Educational Program (IEP). Periodic neurodevelopmental assessments and/or developmental/behavioral pediatric consultation can be an important adjunct to the team evaluation.
  • Thyroid function
  • Fasting lipid profile
  • Routine urinalysis
  • Monitoring for scoliosis
  • Ophthalmologic evaluation
  • Otolaryngologic follow-up for assessment and management of otitis media and other sinus abnormalities
  • Audiologic evaluation at regular internals to monitor for conductive or sensorineural hearing loss

Recommended as clinically indicated:

  • EEG in individuals who have clinical seizures to guide the choice for antiepileptic agent. For those without overt seizures, EEG may be helpful to evaluate for possible sub-clinical events in which treatment may improve attention and/or behavior. A change in behavior or attention warrants re-evaluation.
  • Urologic workup if history of frequent urinary tract infections
  • Neuroimaging (MRI or CT scan) in accordance with findings, such as seizures, and/or motor asymmetry
  • Individuals with SMS documented to have larger deletions:
  • Monitoring for hypercholesterolemia and medical treatment if indicated

Treatment recommendations include the following:

  • Ongoing pediatric care with regular immunizations
  • From early infancy, referrals for early childhood intervention programs, followed by ongoing special education programs and vocational training in later years
  • Therapies including speech/language, physical and occupational, and especially sensory intregration
    • During early childhood, speech/language pathology services should initially focus on identifying and treating swallowing and feeding problems as well as optimizing oral sensory motor development.
    • Therapeutic goals of increasing sensory input, fostering movement of the articulators, increasing oral motor endurance and decreasing hypersensitivity are needed to develop skills related to swallowing and speech production.
    • The use of sign language and total communication programs as adjuncts to traditional speech/language therapy is felt to improve communication skills and also have a positive impact on behavior. The ability to develop expressive language appears dependent upon the early use of sign language and intervention by speech/language pathologists.
  • Published data about the optimal intervention and behavioral strategies in SMS are limited to anecdotal and experiential findings.
    • Use of psychotropic medication may increase attention and/or decrease hyperactivity. No single regimen shows consistent efficacy.
    • Behavioral therapies are integral in behavioral management. Special education techniques that emphasize individualized instruction, structure, and routine can help minimize behavioral outbursts in the school setting.
    • Therapeutic management of the sleep disorder in SMS remains a challenge for physicians and parents. There are no published well-controlled treatment trials. Early anecdotal reports of therapeutic benefit from melatonin remain encouraging. Dosages of 2.5 mg to 5.0 mg (6 mg maximum) taken at bedtime have been tried, providing general improvement of sleep without reports of major adverse reactions. However, melatonin dispensed over-the-counter is not regulated by the FDA; thus, dosages may not be exact. No formal melatonin treatment trials have been conducted. A monitored trial of four to six weeks on low-dose (1-3 mg) melatonin may be worth considerating in affected individuals with major sleep disturbance. A single uncontrolled study of nine patients with SMS treated with oral ß-1-adrenergic antagonists (Acebutolol 10 mg/kg) reported suppression of daytime melatonin peaks and subjectively improved behavior [ DeLeersnyder et al 2001 ]. This treatment, however, did not restore nocturnal plasma concentration of melatonin. A second uncontrolled trial by the same group [ DeLeersynder et al 2003 ] combined the daytime dose of Acebutolol with an evening oral dose of melatonin (6 mg at 8PM) and found that nocturnal plasma concentration of melatonin was restored and nighttime sleep improved with disappearance of nocturnal awakenings. Parents also reported subjective improvements in daytime behaviors with increased concentration. The contraindications to using ß-1-adrenergic antagonists must also be considered, including asthma, pulmonary problems, cardiovascular disease, and diabetes mellitus. Prior to beginning any trial, the child's medical status must be considered. It is also beneficial to have an understanding of the child's baseline sleep pattern.
    • Enclosed bed system (Vail bed)
  • Respite care and family psychosocial support help assure the optimal environment for the affected individual

Developed and adopted by PRISMS Professional Advisory Board and revised 15 March, 2004. Smith-Magenis Syndrome. In: GeneReviews at GeneTests: Medical Genetics Information Resource (database online). Available at http://www.genetests.org

Authors:

Ann CM Smith, MA, DSc (hon), CGC
Judith E Allanson, MD
Albert J Allen, MD, PhD
Elisabeth Dykens, PhD
Sarah H Elsea, PhD, FACMG
Brenda M Finucane, MS, CGC
Kyle P Johnson, MD
James R Lupski, MD, PhD, FAAP, FACMG, FAAAS
Ellen Magenis, MD, FAAP, FACMG
Lorraine Potocki, MD, FACMG
Beth Solomon, MS