Introduction

In a world where the cries of infants are often likened to sweet melodies, the reality for some is far from serene. Imagine instead a baby's cries replaced by high-pitched, cat-like meows.

This unusual scenario is a hallmark of cri du chat syndrome, a rare genetic disorder affecting approximately 1 in 20,000 to 50,000 newborns worldwide.1 Beyond its distinctive cry, individuals with cri du chat syndrome face a multitude of challenges, including significant sleep disturbances that profoundly impact their lives and those of their caregivers.

Understanding cri du chat syndrome

Cri du chat syndrome, also known as 5p- syndrome or cat cry syndrome, arises from a partial or complete deletion (loss of genetic material) of the short arm of chromosome 5.2 The severity of the condition varies depending on the size and location of the deletion, with larger deletions resulting in more pronounced symptoms.2

The hallmark "cat-like" cry that lends its name to the syndrome is one of the most recognisable features, typically present in infancy. This high-pitched, monotonous cry is thought to stem from structural abnormalities in the larynx and pharynx, as well as neurological factors affecting cry regulation.2

In addition to the characteristic cry, individuals with cri du chat syndrome may exhibit a range of physical and intellectual disabilities. Common physical features include downward-slanting eyes and microcephaly (small head circumference).

Intellectual disabilities, ranging from mild to severe, are also common, often manifesting as delays in speech development, communication difficulties, learning challenges, and impaired adaptive behaviour.2

The complexity of sleep disturbance

Sleep disturbances pose a significant concern for individuals with cri du chat syndrome and their caregivers. Research suggests that up to 80% of individuals with the condition experience some form of sleep-related issue, spanning difficulty falling asleep, frequent night wakings, early morning awakenings, and sleep-disordered breathing.3

Physiological factors

Underlying medical conditions contribute to sleep disturbances, with obstructive sleep apnea (OSA) being one of the most common issues.3

In OSA, breathing patterns are disrupted and sleep is fragmented due to partial or complete obstruction of the upper airways.

Structural abnormalities associated with cri du chat syndrome, such as a small jawbone and low muscle tone, increase the risk of OSA by narrowing the airway and reducing its ability to remain open during sleep.3

Additionally, gastro-oesophageal reflux disease (GORD) can cause discomfort and disrupted sleep due to acid reflux.3

Neurological factors

The deletion of genetic material on chromosome 5 can profoundly affect brain development and function, potentially impacting the regulation of sleep-wake cycles.3

Disruptions in the production or regulation of sleep-related hormones, such as melatonin, may also contribute to sleep disturbances.3 Melatonin plays a crucial role in regulating circadian rhythms and promoting sleep. Individuals with cri du chat syndrome may have altered melatonin levels or impaired melatonin signalling pathways, leading to disruptions in their sleep-wake cycles.3

Furthermore, neurological impairments associated with cri du chat syndrome can affect the brain's ability to transition between different sleep stages, resulting in fragmented or non-restorative sleep.3

Behavioural factors

Challenging behaviours exhibited by individuals with cri du chat syndrome can interfere with sleep.3

Anxiety, hyperactivity, and self-injurious behaviours may make it difficult to settle down and fall asleep. Sensory processing issues, common in cri du chat syndrome, can also play a significant role in sleep disturbances, with individuals being hypersensitive to environmental stimuli such as noise, light, or temperature changes.3

Difficulty adhering to consistent sleep routines or engaging in self-soothing behaviours further exacerbates sleep-related challenges.3

The far-reaching impact on life quality

The consequences of sleep disturbances in individuals with cri du chat syndrome extend far beyond the confines of the bedroom. Chronic sleep deprivation can have a cascading effect on various aspects of physical and emotional well-being, impacting both the individuals themselves and their caregivers.4

For individuals with cri du chat syndrome, lack of quality sleep can lead to4:

Fatigue and decreased energy levels

Impaired cognitive function and learning difficulties

Increased irritability, mood disturbances, and behavioural challenges

Weakened immune system

Increased risk of obesity and other health problems

Exacerbation of existing developmental delays and disabilities

Comprehensive management strategies

Addressing sleep disturbances in individuals with cri du chat syndrome requires a multidisciplinary approach that encompasses various strategies and interventions. By adopting a holistic, personalised approach, families and healthcare professionals can work together to improve sleep quality and enhance the overall well-being of these individuals.5

Establish a consistent sleep routine

Implementing a consistent sleep routine can be a powerful tool in regulating the body's internal clock and promoting better sleep patterns. This may involve activities such as a warm bath, gentle massage, calming bedtime stories, or relaxation techniques to help the individual wind down before sleep.

Consistency is key, as individuals with cri du chat syndrome often thrive on predictable routines. Caregivers should aim to establish a consistent bedtime and wake-up time, as well as a relaxing pre-bedtime ritual that signals to the body and mind that it is time to prepare for sleep.5

Create a sleep-friendly environment

Minimising environmental stimuli can be particularly beneficial for individuals with cri du chat syndrome who experience sensory processing issues. Strategies may include:

Using blackout curtains or blinds to block out external light sources

Incorporating white noise machines or fans to mask disruptive sounds

Maintaining a comfortable room temperature

Using breathable bedding materials

Limiting exposure to electronic devices and screens before bedtime

Ensuring a clutter-free and organised sleep environment

By creating a calming and sensory-friendly sleep environment, individuals with cri du chat syndrome may find it easier to relax and fall asleep.5

Implement good sleep hygiene practices

Practising good sleep hygiene can significantly improve sleep quality. This may involve:

Limiting caffeine intake, especially in the late afternoon and evening

Regular physical activity

Exposure to natural light

Avoiding large meals or heavy snacks close to bedtime

Establishing a relaxing pre-bedtime routine, such as taking a warm bath or reading a book

Maintaining a cool, dark, and quiet sleep environment

By incorporating these sleep hygiene practices into daily routines, individuals with cri du chat syndrome may experience improved sleep onset and sleep maintenance.5

Explore complementary therapies

Certain complementary therapies, when used in conjunction with other strategies, may help promote relaxation and improve sleep quality. These may include massage therapy, aromatherapy, and relaxation techniques such as deep breathing exercises, progressive muscle relaxation, or guided imagery.5

Address underlying medical conditions

If sleep disturbances are related to underlying medical conditions, it is crucial to seek appropriate medical treatment to manage these effectively. For individuals with cri du chat syndrome, some common conditions that may contribute to sleep issues include obstructive sleep apnea (OSA) and gastro-oesophageal reflux disease (GORD). Treatment options may include5:

Continuous positive airway pressure (CPAP) therapy

Oral appliances

Surgery

Dietary modifications

Medications

Positional therapy

Consider medication as a last resort

In some cases, when non-pharmacological interventions have been exhausted or are insufficient, medication may be prescribed to help regulate sleep patterns. However, this should be done under the guidance of a healthcare professional.

Melatonin supplements are often considered a first-line option, as they can help synchronise the body's circadian rhythms and promote sleep onset. Other medications, such as antihistamines or sedatives, may be prescribed for short-term use in specific situations, but their long-term use should be carefully evaluated due to potential risks and side effects.

It is important to note that medication should be used in conjunction with other behavioural and environmental strategies, not as a sole solution, and should be regularly evaluated for effectiveness and appropriateness.5

Sleep specialists or sleep clinics

Sleep specialists, such as sleep medicine physicians or sleep technologists, are essential in evaluating and managing sleep disturbances in individuals with cri du chat syndrome. These professionals can:

Conduct comprehensive sleep studies to identify specific sleep disorders or patterns

Recommend appropriate treatment options, such as CPAP therapy or positional devices

Provide guidance on sleep hygiene practices and environmental modifications

Monitor the effectiveness of interventions and adjust as needed

Sleep clinics offer a specialised setting where individuals can undergo thorough evaluations and receive personalised treatment plans.5

Occupational therapists or behavioural therapists

Occupational therapists and behavioural therapists play a vital role in addressing the sensory processing and behavioural challenges that can contribute to sleep disturbances in individuals with cri du chat syndrome.

Occupational therapists can evaluate sensory processing abilities and develop strategies to improve sensory regulation, provide recommendations for environmental modifications and adaptive equipment, and teach self-regulation techniques and coping strategies.

Behavioural therapists can conduct functional assessments to identify the underlying causes of challenging behaviours, develop individualised behaviour intervention plans, and implement strategies such as positive reinforcement, visual supports, and functional communication training.

By addressing sensory and behavioural needs, these therapists can help create an environment more conducive to restful sleep.5

Support groups or counselling services

The journey with cri du chat syndrome can be emotionally and physically demanding for individuals and their caregivers alike. Support groups and counselling services can provide a valuable source of understanding, advice, and shared experiences. Support groups connect families affected by cri du chat syndrome, allowing them to share strategies, resources, and emotional support.

Counselling services, such as psychotherapy or family therapy, can help individuals and caregivers cope with the challenges of managing a rare genetic disorder, including sleep disturbances. These support systems can help alleviate feelings of isolation and provide a sense of community for those navigating the complexities of cri du chat syndrome.5

Summary

Cri du chat syndrome presents unique challenges, including significant sleep disturbances, which profoundly impact the lives of individuals and their caregivers.

However, with a comprehensive and multidisciplinary approach encompassing genetic understanding, environmental modifications, behavioural interventions, and professional support, it is possible to improve sleep quality and enhance the overall well-being of those affected.

By working together and tailoring strategies to individual needs, families and healthcare professionals can navigate these challenges, paving the way for restful sleep and improved quality of life.

References

Sandra, Doria, Xavier., V., Silva., Gabriel, Natan, Pires., Guilherme, L., Fernandes., Sergio, Tufik., Monica, L., Andersen. 0486 Sleep patterns of children with cri du chat syndrome and autism spectrum disorder during the COVID-19 pandemic. Sleep, (2022). doi: 10.1093/sleep/zsac079.483

A.P.H.M., Maas., Robert, Didden., Hubert, Korzilius., W.J., Braam., Marcel, G., Smits., Leopold, M., G., Curfs., Leopold, M., G., Curfs. Sleep in Individuals with Cri du Chat Syndrome: A Comparative Study.. Journal of Intellectual Disability Research, (2009). doi: 10.1111/J.1365-2788.2009.01184.X

Jane, Petty., Chris, Oliver., Joanna, Moss., Patricia, Howlin., P, Tunnicliffe., Gemma, M., Griffith., Richard, P., Hastings. Investigating sleep architecture in Angelman, Cri du Chat and Cornelia de Lange syndromes. Journal of Intellectual Disability Research, (2008). doi: 10.1111/J.1365-2788.2008.01119_15.X

Ajitkumar A, Jamil RT, Mathai JK. Cri Du Chat Syndrome. [Updated 2022 Oct 25]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK482460/

Anthony, Claro., Kim, Cornish., Reut, Gruber. Association between Fatigue and Autistic Symptoms in Children with Cri du Chat Syndrome. American Journal on Intellectual and Developmental Disabilities, (2011). doi: 10.1352/1944-7558-116.4.278