Introduction

Cri du Chat Syndrome (CdCS) is a rare genetic condition that affects one of the chromosomes in a patient's body. A chromosome is a thread-like structure in the cells of all humans that contains DNA and carries genetic information from cell to cell.¹ In CdCS, there is a missing part of the short arm of one of the chromosomes leading to missing genetic information and this causes the traits, which characterize the condition such as distinctive facial features, a delay in development, and intellectual disability.²

As a result of these characteristic traits, feeding difficulties in individuals with CdCS are common. Parents may struggle to feed their child in their first year of life and the move from pureed to solid foods may take longer than usual.³ However, the severity of the condition affects the extent to which children and adolescents struggle with feeding and the correct information can make the experience easier. This article will clarify the relationship between CdCS and feeding difficulties and provide management interventions and practical support for carers of affected individuals.

Understanding Cri du Chat syndrome

Definition and causes of CdCS

Cri du Chat Syndrome is a rare genetic condition caused by the absence of the short arm (also known as the petit/p arm) of chromosome 5. The condition can therefore also be known as 5p- (5p minus) syndrome to describe the deleted part of the chromosome.⁴ The name ‘Cri du Chat’ translates to ‘Cry of the Cat’ in French and originates from the distinctive high-pitched cry made by affected babies.

Most deletions occur randomly and are not the fault of anything the parents have done or not done. Furthermore, the parents and extended family of the child usually do not have the deletion in their own chromosomes.⁴

Common characteristics and symptoms

The characteristic cat-like cry present in newborns is caused by the anatomical differences of the voicebox (larynx ) in individuals with the condition such as an underdeveloped or narrowed voicebox.² In some cases it may be a result of neurological changes associated with the syndrome.⁵

The Cleveland Clinic lists some of the common symptoms of CdCS:

Facial features: Small head (microcephaly), eyes which are far apart, ears positioned lower down, short gap between the nose and mouth (philtrum), moon face, crossed eyes, eyelids that face down (palpebral fissures), and a small jaw

• Weighing less than usual at birth
• Prolonged growing and development
• Weak muscle tone (hypotonia) at birth, which may become high muscle tone (hypertonia) as they get older
• Scoliosis
• Heart defects: patent ductus arteriosus
• Psychomotor and intellectual disability
• Problems with speech and communication

Although some patients may deal with serious medical conditions, most people will have a normal life expectancy.⁶

Impact on development and daily life

These symptoms can have a direct effect on the daily activities of people with CdCS. Problems with psychomotor activities involve those that require mental and muscular abilities and are typically assessed as developmental milestones such as the holding up of the head, sitting up and walking.⁷

Moderate to severe intellectual disability often affects patients. This means that they may struggle with cognitive functions like reasoning, problem-solving, and learning; the onset of which occurs during childhood.⁸

Individuals may also struggle with adaptive behaviours such as everyday tasks, behavioural difficulties, and speech delays.

It is important not to generalize and assume what individuals can or cannot do, especially because CdCS is a spectrum disorder with varying degrees of severity dependant on where the portion of the chromosome that was deleted was and its size.⁶,⁹

Feeding difficulties in Cri du Chat syndrome

Factors contributing to feeding difficulties

As Cri du Chat Syndrome affects so much of daily life, it isn’t surprising that individuals may have feeding difficulties. Parents may struggle to feed their baby because of their low muscle tone, poor sucking cooperation, and gastroesophageal reflux disease (GERD).⁷

A poor sucking response may be due to children being unable to suck and breathe simultaneously or because of their weak muscle tone.¹⁰

Children and adolescents with the condition are at higher risk of respiratory infections which may be linked to this reflux.³

Furthermore, problems with chewing and swallowing result in a delayed start on solid foods with 37% of children and adolescents on a study always eating pureed food.³ The risk here is that the initial feeding problem caused by the anatomical abnormalities can result in ingrained behaviour patterns, so it is crucial that parents are informed of the developmental signs to look out for when starting their child on solid food.¹⁰

Potential impact on nutrition and overall health

Babies born with CdCS might be lighter and shorter than other babies however when measuring their weight against their height in the form of a Body Mass Index, most babies weren’t shockingly thin.¹⁰ Studies are unsure how much of their small frame is due to genetics or inadequate nutrition.¹⁰

Feeding difficulties could lead to failure to thrive in infants. A study found that protein-energy malnutrition is poorly reported in the condition yet common, especially early on, and requires close nutritional monitoring.¹¹

Another study found a link between the thinner a baby was from lack of food, the more obvious their small head circumference and therefore emphasized growth and nutrition monitoring.¹²

Assessment and diagnosis of feeding difficulties

Importance of early identification and assessment

Children with CdCS benefit from early intervention which focuses on their individual needs and therefore an early diagnosis of CdCS and identification of feeding difficulties is important.

Evaluation methods used by healthcare professionals

Diagnosis of CdCS occurs through a clinical diagnosis. Feeding difficulties are usually self-reported by the parents of the child, yet sometimes a barium swallow test can be used to test swallowing ability and reduce the chances of aspiration pneumonia.¹³

A GP or paediatrician may carry out a formal assessment to widen your understanding of your child’s needs, skills, and development. This will be followed by a support plan which targets these delays in specific areas of development.¹⁴

Management and intervention strategies

Multidisciplinary approach to managing feeding difficulties

A combination of therapies is used and these may change as the child continues to develop.¹⁴ Correcting protein-energy malnutrition not only involves nutritional monitoring but also swallowing education from a speech therapist.¹³ Speech therapy not only helps in communication but develops the skills of chewing, sucking, and swallowing.¹⁴

Most children with CdCS will reach developmental milestones, they might just need extra time and support. Occupational therapy and physiotherapy can be useful in supporting motor coordination and life skills and may positively impact feeding.¹³

Nutritional interventions and dietary considerations

A feeding tube may be placed to prevent failure to thrive and breastfeeding counsellors may be accessed to improve the experience.

Gastroenterologists will help manage gastrointestinal problems such as reflux and constipation while dieticians will adjust a diet plan to account for the child’s individual requirements including low mouth and food pipe muscle tone.¹³

Problems in infants can usually be safely treated in their hospital units and intensive care is rare.¹⁵ If problems with sucking and swallowing are present in newborns, physical therapy is started within the first few weeks.¹⁵ Further investigations may be done if malformations of the larynx (voice box) or epiglottis (leaf-shaped covering which prevents food from entering your lungs) are present.¹⁵

Behavioural and sensory-based strategies for improving feeding

It is important to remove any pain or discomfort resulting from reflux or constipation to prevent it from contributing to self-injurious or aggressive behaviors.¹³

Some things to look out for for parents to indicate pain include:

• Distressed facial expression
• Leg movements
• Crying in which soothing doesn’t work
• Bursts of aggressive behavior ‘out of the blue’

Practical tips for parents and caregivers

Practical tips for parents include creating a supportive feeding environment in which the child feels comfortable and techniques which may promote successful feeding. Parents can use a syringe to clean excess mucus from the child’s passageways before feeding.¹⁰ Making sure the baby has fully woken up and supporting the baby’s chin may help them in sucking.¹⁰

Ongoing research

There is research into further interventions which could be used to support children with feeding difficulties. A single-subject study looked at the effects of oral stimulation (such as the tongue and inner cheeks) on feeding difficulties and concluded that it contributed to the normal feeding development of the child, stimulated the transition from the feeding tube to bottle feeding and resulted in a shortened hospital stay.¹⁶

Summary

Feeding difficulties are one of the developmental problems children born with Cri du Chat syndrome may struggle with. These are caused by factors such as poor muscle tone and poor sucking cooperation and reflux. Feeding difficulties can cause failure to thrive or a smaller head circumference. Early identification of difficulties is important to ensure early intervention which is a range of multidisciplinary therapies. Management includes speech therapy and occupational therapy interventions as well as nutritional treatment such as feeding tubes. Parents can help by assessing whether behaviours are a sign of physical pain related to reflux, creating a supporting feeding environment and using practical tips to make sucking easier for their infant.