Introduction

One of the most frequent chromosomal defect syndromes, Cri-du-chat syndrome (CdCS), is caused by the deletion of the short (p) arm of chromosome 5. It is thought to affect 1 in 15,000–50,000 live births. On the clinical level, CdCS is usually recognized as a high-pitched cry, low birth weight, microcephaly, and hypotonia throughout infancy.

Cri Du chat syndrome

Cause

It is a genetic disorder. The French phrase "Cri du chat" translates to "Cry of the cat". A missing chromosomal fragment causes the unusual genetic condition of genetic loss on chromosome 5's small arm has been designated as 5p. The symptoms might vary from moderate to severe depending on the location and extent of the deletion.¹

Symptoms² and characteristics

the main clinical features of CdCS are well known, the neurocognitive and behavioural characteristics of the phenotype are:

Craniofacial malformations³

• Microcephaly: which is a small head
• Moon face
• Hypertelorism: an increased distance between eyes
• Prominent epicanthic folds: a skin fold of the upper eyelid covering the inner corner of the eye. 
• Large nasal bridge
• Downturned corners of the mouth
• Short philtrum: a shorter-than-normal distance between the upper lip and the nose
• Premature grey hair
• Abnormal transverse flexion creases

Uncommonly:

• Downward slanting palpebral fissures
• Low-set ears
• Narrow auditory ducts
• Preauricular tags
• Deafness
• Myopia and cataracts
• Hypersensitivity of pupils to methacholine
• Hypospadias⁴ and cryptorchidism⁵

With increasing age, the following features change:

• Hypotonia in the neonatal period is replaced with hypertonia
• Prominent microcephaly
• Prominent supraorbital arch
• Dental malocclusions
• Moon's face changes into a more narrow vertical face in adulthood

Other anomalies that might be present

• Hypersensitivity to sound
• Cardiac disorders, including congenital heart defects
• Cutaneous hemangioma
• Renal pathology

Orofacial abnormalities

• High palate
• Mandibular microretrognathia
• Hypoplasia of the enamel
• Chronic periodontitis

Developmental and behavioural manifestations

• Hyperactivity
• Self-injurious behaviour
• Repetitive movements
• Gentle personality
• Obsessive attachment to objects
• Comprehension of speech is better than their ability to express or communicate

The survey was sent to 700 Brazilian families registered with the Brazilian CDCS Association. The age at diagnosis of CdCS ranged from birth to 180 months, while one case was diagnosed during pregnancy. In all cases, the diagnosis of CdCS was made by G-band karyotype analysis.

The main health problems reported were: swallowing difficulties, feeding problems, congenital heart disease, spinal cord abnormalities and neurological symptoms including seizures. The questionnaire was a pioneering initiative of the CdCS Support Group, and the responses used in this study may improve the health of these patients by focusing on the demands of parents.

Distinctive facial features, intellectual disabilities, delayed development, etc.

Heart defects in cri du chat syndrome

In a retrospective review of 98,422 cases of congenital heart disease, 21 cases of postnatal CdCS associated with heart defects were reported. 

Types of heart defect

• Ventricular septal defect
• Patent ductus arteriosus
• Tetralogy of Fallot
• Pulmonary valve atresia with ventricular septal defect
• Pulmonary valve stenosis
• Right ventricular double outlet

Defects showed a significantly higher proportion of patients with CDC syndrome than patients with these specific defects. there is no clear understanding of the prevalence of these defects in the genomic CDC population.

Management and treatment

Prenatal diagnosis

It can be diagnosed before birth by ultrasound or by testing the baby's chromosomes during pregnancy “Amniocentesis, Chorionic Villus Sampling” and Ultrasound Scan.

Postnatal diagnosis

Postnatal diagnosis is done by tests if the baby shows signs of cri du chat syndrome. See the separate leaflet called Genetic Testing. Parents of a child with Cri du chat syndrome should also receive genetic counselling and testing to determine if one parent has the mutation on chromosome 5.

Further tests are needed to evaluate signs associated with Cri du chat syndrome, such as skull X-rays. and magnetic resonance imaging (MRI) to evaluate craniofacial abnormalities) or cardiac ultrasound (echocardiogram) to evaluate heart defects).

There is no specific treatment for Cri du chat syndrome. However, affected infants and children may require extensive physical therapy and speech and language therapy. In general, people with Cri du chat syndrome have a normal life expectancy. However, it is important to note that related health problems, especially heart damage and breathing difficulties, can affect longevity. Regular medical care and preventive disease management are essential to maintaining good health.

Cardiac evaluations and monitoring for individuals with Cri Du chat syndrome

The sonography  

Suggested here can facilitate the identification of CdCS or enable early detection through chromosomal testing, particularly in situations where there is no clear indication for a cessation of analysis.

Electrocardiogram 

Pulse oximetry 

Surgical intervention and therapeutic options for heart defects

• Congenital heart defects could be addressed through appropriate treatment. Medical problems associated with minor deformities such as strabismus and flat feet can be corrected surgically. Orchiopexy⁶ may be necessary in patients with undescended testes.
• Anaesthetic plan issues that are significant include airway abnormalities, congenital heart disease, hypotonia, intellectual disability, and temperature regulation.

Multidisciplinary approach to comprehensive care and support

Support services for parents of children with disabilities include:

• Counselling: follow up with paediatric doctors
• Information: acknowledgement to the parents on how to care for their special child
• Referral: your family doctor may send your child to different specialist doctors such as cardiologists, ENT specialists, psychiatrists neurologists etc. 
• Physiotherapist
• support groups for special child parents

Conclusion

A missing chromosomal fragment causes the unusual genetic condition known as "cri du chat syndrome," sometimes known as "cat cry syndrome."heart condition types that are frequently linked to ventricular septal abnormalities in the syndrome. Genetic counselling and testing should be provided to parents of a child with Cri du chat syndrome in order to determine whether one of the parents has a chromosome 5 mutation. Additional testing will be required to evaluate any characteristics linked to Cri du chat syndrome (such as an ultrasound scan of the heart to evaluate any cardiac anomalies or an assessment of any abnormalities in the skull and face).