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PubMed This is a summary of 66 peer-reviewed journal articles Updated
Medical Genetics

Smith-Magenis Syndrome: A Patient Guide

At a Glance

Smith-Magenis syndrome is a lifelong genetic condition usually caused by a chromosome 17 deletion involving RAI1. A reversed melatonin pattern can disrupt sleep, mood, learning, and behavior, making early intervention, medical monitoring, and coordinated family support important.

Smith-Magenis Syndrome (SMS) is a rare, complex neurodevelopmental disorder that affects many different systems within the body. It is caused by a genetic change involving the RAI1 gene on chromosome 17—most often a small missing piece of the chromosome called a deletion, or more rarely, a tiny spelling error known as a pathogenic variant [1][2]. Because the RAI1 gene (along with neighboring genes in deletion cases) plays an important role in regulating how the brain and body develop, its alteration leads to a distinct set of physical, developmental, and behavioral traits [3]. Note that while this guide focuses on parents and caregivers of children newly diagnosed, SMS is a lifelong condition, and support spans through adolescence and into adulthood.

A profound feature of SMS is a unique “flipped” internal clock, known as an inverted melatonin rhythm [4]. While most people produce melatonin to sleep at night, individuals with SMS often produce it during the daylight hours, leading to daytime sleepiness and a natural tendency to wake up very early in the morning [5][6]. This chronic disruption of sleep is not just a nighttime challenge; it is a biological driver that deeply influences mood, learning, and behavior throughout the day [7].

Living with SMS also means navigating a specific neurobehavioral profile that commonly includes intellectual disability, impulsivity, and social-seeking tendencies [8][9]. Some children also develop characteristic behaviors such as self-injury or the urge to insert small objects into body orifices [10]. It is vital for families to understand that these behaviors are rooted in the syndrome’s biology and are often exacerbated by exhaustion or hidden pain, rather than being acts of willful misconduct [11]. Recognizing behavior as a form of communication is a cornerstone of supporting a child with SMS [12].

Beyond the brain and behavior, SMS is a multisystem condition that requires careful medical monitoring [13]. Children often face challenges with hearing and vision, skeletal issues like scoliosis, and metabolic concerns such as a high risk for obesity [14][15]. Because these needs are diverse, care is best managed by a multidisciplinary team of specialists who can tailor treatments to the specific “SMS phenotype,” focusing on improving function and quality of life for the entire family [16][17].

While the road following an SMS diagnosis involves a steep learning curve, it is also a path filled with hope and community. Children with SMS are often described as having affectionate, engaging personalities and a remarkable sense of humor [18]. By combining early intervention, specialized medical care, and a supportive environment, families can help their children reach their full potential.

(Note: The bracketed codes throughout this guide—e.g., [1]—refer to specific medical literature and clinical research identifiers that support the information provided. These correspond to published clinical studies and consensus guidelines.)

In this guide

6 chapters

01

Welcome to the SMS Community: An Orientation for Parents and Caregivers

Learn about Smith-Magenis syndrome, its genetic causes, early signs, sleep and behavior patterns, and practical support options for children and caregivers.

02

The Genetics of Smith-Magenis Syndrome

Learn how Smith-Magenis syndrome genetics explains 17p11.2 deletions and RAI1 variants, FLCN testing, genetic reports, and subtype-specific care for families.

03

Behavior as Communication: The SMS Neurobehavioral Profile

Learn how behavior communicates unmet needs in Smith-Magenis syndrome, including aggression, self-injury, food seeking, sleep debt, and functional behavior analysis

04

Navigating the Flipped Clock: Sleep in Smith-Magenis Syndrome

Learn why Smith-Magenis syndrome flips the melatonin clock, how sleep apnea is checked, and which routines and medicines may help improve sleep safely.

05

Whole-Body Care: Monitoring Health and Recognizing Red Flags

Learn how Smith-Magenis syndrome affects whole-body health, including hearing, vision, scoliosis, heart, metabolism, kidneys, constipation, and emergency signs.

06

Assembling Your Team: Care Coordination and Family Support

Learn how to coordinate Smith-Magenis syndrome care, build a specialist team, support school needs, find respite, and plan for transition to adulthood.

Common questions in this guide

What causes Smith-Magenis syndrome?
Smith-Magenis syndrome is usually caused by a missing section of chromosome 17 that includes the RAI1 gene. Less often, it results from a disease-causing change in RAI1 without a larger deletion. A child’s specific genetic finding can help the care team plan monitoring and support.
Why does Smith-Magenis syndrome cause unusual sleep patterns?
Many people with Smith-Magenis syndrome have a reversed melatonin pattern: their bodies may release more melatonin during the day than at night. This can cause daytime sleepiness and a natural tendency to wake very early. Ongoing sleep disruption can also affect mood, learning, and behavior.
What behaviors may occur in children with SMS?
Children with SMS may have impulsivity, strong social-seeking behavior, self-injury, or an urge to place small objects in body openings. These behaviors are linked to the syndrome and may worsen with exhaustion or hidden pain, so they should not be treated simply as willful misbehavior. Viewing behavior as communication can help caregivers and clinicians identify what support is needed.
What health problems should be monitored in Smith-Magenis syndrome?
Monitoring may include sleep, development and behavior, hearing, vision, the spine for scoliosis, and weight because obesity risk is increased. A multidisciplinary team can coordinate these needs and adjust care as a child grows.
What support helps children with Smith-Magenis syndrome?
Early intervention, specialized medical care, and a supportive environment can help a child build skills and improve quality of life. Families may also benefit from coordinating information with schools and other caregivers and connecting with SMS-specific resources or support groups.
Is Smith-Magenis syndrome lifelong?
Yes. Smith-Magenis syndrome is a lifelong condition, so support may need to continue through childhood, adolescence, and adulthood. Care plans can change over time as sleep, behavior, learning, and medical needs change.

Questions For You

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Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.What is the specific genetic cause of my child's SMS (a deletion or a pathogenic variant), and how does that guide our care?
  2. 2.How can we coordinate a team of specialists to address my child's sleep, behavior, and medical needs together?
  3. 3.Are there local or regional resources and support groups specifically for families living with SMS?
  4. 4.What are the most effective ways to share information about SMS with my child's school and other caregivers?

References

References (18)
  1. 1

    Smith-Magenis Syndrome-Clinical Review, Biological Background and Related Disorders.

    Rinaldi B, Villa R, Sironi A, et al.

    Genes 2022; (13(2)) doi:10.3390/genes13020335.

    PMID: 35205380
  2. 2

    Deletion of RAI1 noncoding exons 1-2 causes Smith-Magenis syndrome.

    Hamiel U, Kurolap A, Gadot CC, et al.

    Journal of genetics 2025; (104()).

    PMID: 40386916
  3. 3

    Molecular and Neural Functions of Rai1, the Causal Gene for Smith-Magenis Syndrome.

    Huang WH, Guenthner CJ, Xu J, et al.

    Neuron 2016; (92(2)):392-406 doi:10.1016/j.neuron.2016.09.019.

    PMID: 27693255
  4. 4

    Twenty-four-hour motor activity and body temperature patterns suggest altered central circadian timekeeping in Smith-Magenis syndrome, a neurodevelopmental disorder.

    Smith ACM, Morse RS, Introne W, Duncan WC

    American journal of medical genetics. Part A 2019; (179(2)):224-236 doi:10.1002/ajmg.a.61003.

    PMID: 30690916
  5. 5

    A cross-syndrome cohort comparison of sleep disturbance in children with Smith-Magenis syndrome, Angelman syndrome, autism spectrum disorder and tuberous sclerosis complex.

    Trickett J, Heald M, Oliver C, Richards C

    Journal of neurodevelopmental disorders 2018; (10(1)):9 doi:10.1186/s11689-018-9226-0.

    PMID: 29490614
  6. 6

    Adrenocorticotropic Hormone Therapy Improved Spasms and Sleep Disturbance in Smith-Magenis Syndrome: A Case Report.

    Momosaki K, Kido J, Matsumoto S, et al.

    Pediatric reports 2020; (12(3)):72-76 doi:10.3390/pediatric12030018.

    PMID: 33114276
  7. 7

    Sleep disturbances and behavior in Smith-Magenis syndrome.

    Garayzábal E, Hidalgo I, Miranda de Souza ALD, et al.

    Research in developmental disabilities 2022; (128()):104286 doi:10.1016/j.ridd.2022.104286.

    PMID: 35779287
  8. 8

    The prevalence of neurodevelopmental disorders in Smith-Magenis Syndrome: a PRISMA compliant systematic review.

    Boiroux P, Babinet MN, Chesnoy G, et al.

    Journal of neurodevelopmental disorders 2026; (18(1)).

    PMID: 42226112
  9. 9

    Heterogeneity of Autism Characteristics in Genetic Syndromes: Key Considerations for Assessment and Support.

    Jenner L, Richards C, Howard R, Moss J

    Current developmental disorders reports 2023; (10(2)):132-146 doi:10.1007/s40474-023-00276-6.

    PMID: 37193200
  10. 10

    Behavioral disturbance and treatment strategies in Smith-Magenis syndrome.

    Poisson A, Nicolas A, Cochat P, et al.

    Orphanet journal of rare diseases 2015; (10()):111 doi:10.1186/s13023-015-0330-x.

    PMID: 26336863
  11. 11

    Smith-Magenis syndrome and its circadian influence on development, behavior, and obesity - own experience.

    Chen L, Mullegama SV, Alaimo JT, Elsea SH

    Developmental period medicine 2015; (19(2)):149-56.

    PMID: 26384114
  12. 12

    [Smith-Magenis syndrome is an association of behavioral and sleep/wake circadian rhythm disorders].

    Poisson A, Nicolas A, Sanlaville D, et al.

    Archives de pediatrie : organe officiel de la Societe francaise de pediatrie 2015; (22(6)):638-45.

    PMID: 25934608
  13. 13

    Smith-Magenis syndrome: Clinical and behavioral characteristics in a large retrospective cohort.

    Rive Le Gouard N, Jacquinet A, Ruaud L, et al.

    Clinical genetics 2021; (99(4)):519-528 doi:10.1111/cge.13906.

    PMID: 33368193
  14. 14

    Auditory Phenotype of Smith-Magenis Syndrome.

    Brendal MA, King KA, Zalewski CK, et al.

    Journal of speech, language, and hearing research : JSLHR 2017; (60(4)):1076-1087 doi:10.1044/2016_JSLHR-H-16-0024.

    PMID: 28384694
  15. 15

    Clarifying main nutritional aspects and resting energy expenditure in children with Smith-Magenis syndrome.

    Proli F, Sforza E, Faragalli A, et al.

    European journal of pediatrics 2024; (183(10)):4563-4571 doi:10.1007/s00431-024-05715-z.

    PMID: 39162735
  16. 16

    Neurodevelopmental Disorders Associated with Abnormal Gene Dosage: Smith-Magenis and Potocki-Lupski Syndromes.

    Neira-Fresneda J, Potocki L

    Journal of pediatric genetics 2015; (4(3)):159-67 doi:10.1055/s-0035-1564443.

    PMID: 27617127
  17. 17

    Caregivers' experience of sleep management in Smith-Magenis syndrome: a mixed-methods study.

    Agar G, Bissell S, Wilde L, et al.

    Orphanet journal of rare diseases 2022; (17(1)):35 doi:10.1186/s13023-021-02159-8.

    PMID: 35120534
  18. 18

    Parental experiences with behavioural problems in Smith-Magenis syndrome: The need for syndrome-specific competence.

    Nag HE, Hoxmark LB, Nærland T

    Journal of intellectual disabilities : JOID 2019; (23(3)):359-372 doi:10.1177/1744629519847375.

    PMID: 31046579

This page is for informational purposes only and does not constitute medical advice about your child’s Smith-Magenis syndrome. Discuss genetic findings, sleep, behavior, and medical monitoring with your child’s care team.