Cri Du Chat Syndrome Symptoms in Children

Introduction

Genetic disorder is a disease that occurs when there are changes in DNA sequence - deviates from the normal DNA sequence. This is often due to mutations affecting one or more genes, the interplay of genetic mutations and environmental factors, or problems with the structure or number of chromosomes.¹

Have you heard of the ‘cry of the cat’ syndrome? Cri du Chat syndrome is a rare genetic disorder as a result of changes caused in the chromosome structure. Its name, meaning cry of the cat in French, comes from the main symptom displayed: a high-pitched, cat-like cry. While the condition is rare, it is one of the most commonly observed deletion syndromes in humans, with an incidence ranging from 1 in 15,0000 to 1 in 50,0000 in newborn infants.^2,3 This article will focus on exploring this syndrome, particularly its manifestation in children. 

Description of cri du chat syndrome 

Cri du Chat syndrome occurs due to a deletion of a segment of chromosome 5, resulting in the loss of genetic material. In about 85% of cases, this deletion happens spontaneously, meaning it’s not inherited from the parents. Typically, if it is inherited it usually comes from the father. Occasionally, one parent may be a ‘carrier’, a carrier may have a chromosome rearrangement that does not affect their health but there is a risk that they can pass this rearrangement to their children. Genetic counselling may be recommended to assist in understanding whether you are affected by a genetic condition, at risk for one, or a carrier, which can aid in making informed health decisions.^2,4

Based on reported literature data, the table below outlines the estimated incidence rate, mortality rate, and proportion of deaths occurring within the first year among newborn infants with Cri du Chat syndrome.

Table 1: Incidence and mortality rates of Cri du Chat syndrome 

Although approximately 90% of newborns with Cri du Chat syndrome do not survive beyond the first year, as they age past this critical period, the rates of illness and death decrease significantly as they grow older.² 

The majority of individuals with the condition can live well into adulthood. However, it’s important to note that many experience severe disabilities. Moreover, survival rates for individuals with this condition into adulthood are increasing, with literature reporting a case of an individual living into their 70s.^4,5,6

Symptoms of cri du chat syndrome in children 

Vocal symptom

• At diagnosis, a high-pitched, cat-like cry is frequently observed⁴

Physical symptoms 

Children with Cri du Chat often display the following physical characteristics:⁴ 

• round face
• unusually prominent forehead (metopic bossing)
• large nose bridge
• downward slanting eye openings (downward slanting palpebral fissure)
• wide-set eyes (hypertelorism) 
• skin folds covering the inner corners of the eyes (epicanthal folds) 
• down-turned corners of the mouth 
• short philtrum 
• low-set ears
• eye squint (strabismus divergent/convergent)
• short neck
• undersized lower jaw (micrognathia)³

Other features 

• Low birth weight and slow growth⁴
  • Children with Cri du Chat syndrome often present with low birth weight and demonstrate slow growth over time

• Microcephaly (small head size)⁴
  • Microcephaly is a congenital condition where a baby’s head is smaller than usual for its age and gender. Babies with microcephaly often have smaller brains because their brains are not fully developed.

• Decreased/low muscle tone (hypotonia)⁴

Developmental delays

• Children with cri du chat typically understand speech better than they can express or communicate themselves
• Significant delays in both physical movement and mental abilities.
• Auditory or visual impairments
• Intellectual disabilities^2,3,4 

Behavioural symptoms 

Children with Cri du Chat syndrome may exhibit a range of behavioural characteristics. They may display a high level of activity (i.e. hyperactivity), constantly moving around and finding it difficult to stay still for extended period of time. Additionally, they might engage in self-injurious behaviour, such as hitting or biting or scratching themselves. Repetitive movements are also common, where the child may repeatedly perform certain actions or gestures without any apparent purpose. Furthermore, they may develop an obsessive attachment behaviour to specific items, becoming intensely fixated on them. Some children may display aggressive behaviour, while others may display a calm and kind demeanour.^2,7,8

Health issues 

The following health issues associated with Cri du Chat syndrome include abnormalities in organs, particularly the heart, potentially affecting the functioning of other vital organs within the body. Furthermore, other complications can involve scoliosis which may lead to posture and mobility issues.² 

Diagnosis and evaluation 

Confirmation of diagnosis of Cri du Chat syndrome can be achieved through the recognition of particular characteristics and symptoms listed above, during clinical evaluation.  In some cases, when clinical evaluation is not possible karyotype analysis can confirm diagnosis.  Further testing, such as fluorescence in situ hybridisation (FISH), comparative genomic hybridisation (CGH), and quantitative polymerase chain reaction (qPCR) may be conducted when there is a strong clinical suspicion of a Cri du Chat syndrome despite the presence of a normal karyotype during analysis. Genetic counselling is typically offered as part of the diagnostic process for Cri du Chat syndrome. During genetic counselling, families are informed about the purpose, expected outcomes and limitations of diagnostic tests and analyses. Additionally, they receive information about the genetic basis of the condition, the likelihood of its recurrence in future pregnancies and the available resources to support them.^2,4

Management and treatment 

Patients may benefit from rehabilitation and support services for early intervention:² 

• Therapies (e.g., physical, auditory, speech, psychomotricity)
• Educational assistance and support groups for families 
• Genetic counselling 

Summary 

• Cri du Chat syndrome is a genetic condition resulting from the deletion of a portion of chromosome 5. One of the most common symptoms observed in children with Cri du Chat syndrome is a high-pitched, cat-like cry. Other symptoms can be observed through low birth weight, slow growth, microcephaly, and low muscle tone (hypotonia). Additionally, distinctive physical characteristics such as a round face and unusually prominent forehead may be observable.  
• While the majority of individuals with the condition can live well into adulthood, approximately 90% of newborns affected by the condition do not survive beyond the first year, with mortality rates decreasing significantly as they age. 
• Clinical diagnosis along with further tests can be provided to confirm Cri du Chat syndrome. 
• Genetic counselling is recommended for families affected by Cri du Chat syndrome to provide information, support and guidance regarding the condition. 
• Management and treatment options for the condition include physical therapy, auditory interventions, and speech therapy, aiming to enhance prognosis and facilitate social adjustment.