Cri-Du-Chat Syndrome - Causes, Symptoms, Diagnosis, and Management

What Is Cri-Du-Chat Syndrome?

Cri-du chat syndrome is a disorder that directly affects the growth and development of infants. It is a rare disorder caused when one portion of chromosome 5 is either deleted or is missing. The most common symptom associated with this disorder is cat-like high-pitched cry, hence the name cri-du chat syndrome.

Also, the newborns face difficulties related to breathing and feeding from the time of birth. However, the symptoms depend on the missing or deletion of the genes. Children with this condition often face changes related to speech development, behavioral issues, and intellectual disabilities. The study shows that the condition is more commonly found in girls, and there are one in 50,000 births found to be affected by this condition.

What Are the Causes of Cri-Du-Chat Syndrome?

• It is caused by the deletion of chromosome 5. Since the process of deletion of the chromosome is not genetically inherited, there is no risk of passing on the faulty genes to the next generation. During this mutation, the end of the short arm (p) of chromosome 5 is deleted, and so it is also referred to as 5p.

• Chromosomes are located at the center of the cells, and they carry independent genetic information of each individual. There are a total of 23 pairs (a total of 46 numbers) of chromosomes present in one cell; in which the 23rd chromosome is known as the sex chromosome. Sex chromosome individually is made with one X and one Y chromosome in males and two X chromosomes in females. There are two arms of the chromosomes, where the shorter one is called “p,” and the longer one is called “q.” Furthermore, the chromosomes are further subdivided into a plethora of bands individually that specify the location of thousands of genes.

• In cri-du chat syndrome, the location and the length of the deleted portion of chromosome 5 define the severity of the condition. For instance, if there are symptoms of intellectual disability in the infant, it might be because of the deletion of chromosome 5 located on band 15.

• Also, there is no particular reason behind the deletion of a specific band location on chromosome 5. However, almost 90 % of the deletion is a paternal process in origin. This means that sperm formation plays an essential part in the formation of this type of mutation. The chromosomal analysis can reveal if the rest, ten percent of the chances, are determined by the balanced translocation of the chromosomes. Translocation is the process of breaking off and rearrangement of particular regions of chromosomes.

What Are the Signs and Symptoms of Cri-Du-Chat Syndrome?

The disorder affects multiple systems, and that is why there are many distinctive clinical features associated with the syndrome, such as:

• Growth and development:

  • Abnormality of Voice: Almost all the cases of cri-du chat syndrome represent this symptom. Children with this symptom also have high-pitched voices and abnormal cat-like crying.

  • Intellectual Disability: Intellectual disability is when the person loses their ability to adaptive functioning and intellectual function. The syndrome usually shows mental retardation related to the condition.

  • Developmental Delays: Children with this syndrome have difficulty achieving the milestones of mental and motor development.

  • Intrauterine Growth Delay: The intrauterine growth of the fetus is compromised due to developmental delays that result in abnormally low weight and height of the fetus.

• Musculoskeletal:

  • Hypotonia: In the relaxed position, the muscles have a continuously passive contraction that gives resistance to their passive stretching. Hypotonia is a peculiarly low muscle tone in the body that results in a failure to resist the passive stretching of the muscles.

  • Scoliosis: It is the condition where there is an unusual lateral curvature of the spine seen.

  • Short Height: Due to intrauterine growth delay, the height of the fetus is also compromised.

  • Abnormal Bone: The disorder is often associated with a complication such as decreased density of the bone due to inhibited bone mineralization and ossification.

  • Finger Syndactyly: It is the condition where the fusion of the fingers is seen. The fusion is either associated with soft tissue or bone.

  • Joint Hyperflexibility: Occasionally, there is abnormally increased movement and flexibility of the joints seen.

• Facial:

  • Abnormality Related to Ears: There is an abnormal appearance of the ears seen with the syndrome, where the ears are located lower and posteriorly rotated than normal.

  • Abnormal Nasal Bridge: The nasal bridge appears to be wider than normal with this condition.

  • Palpebral Fissure: Palpebral fissure is the space between the medial and lateral canthi of the two open eyelids, and children with this syndrome have a more inclined appearance than usual.

  • High Palate: The disorder shows the deep palate associated with the condition.

  • Hypertelorism: It is the condition where the orbits are located at an abnormally far lateral distance.

  • Epicanthus: It is a fold of skin that covers the upper eyelids and inner corner of the eye; due to this, the appearance of the eyelids is abnormally more prominent.

• Cardiovascular:

  • Cardiovascular System Defect: Often, cri-du chat syndrome condition is associated with this disorder, which can be proved to be fatal due to cardiovascular malformation. The condition shows symptoms such as shortness of breath in newborns.

How to Diagnose Cri-Du-Chat Syndrome?

• Medical History: Although the condition is not inherited, it is safe to take a medical history to note down the parents’ complaints, which can be useful for the further evaluation process.

• Physical Examination: It is the most important step after the medical history, as it reveals the signs and symptoms the newborn is facing. There are many distinctive symptoms of this condition that can aid the evaluation process. For instance, the cat-like cry, short stature, or the skiing tag located at a specific location.

• Laboratory Testing: Laboratory testing such as chromosomal analysis can reveal information about the deleted portion and the location of the chromosome. Moreover, the test named fluorescence in situ hybridization (FISH) can be useful in identifying the cri-du chat syndrome.

• Imaging: The radiographic evaluation such as X-rays can reveal the abnormality related to the bones (scoliosis).

How to Manage Cri-Du-Chat Syndrome?

• The standard treatment plan for the syndrome is completely influenced by the severity of the symptoms associated with the condition. A primary care pediatrician can diagnose the symptoms and then refer to a specific specialist, such as an ophthalmologist, neurologist, dentist, and physical or occupational therapist. For instance, if a child with this condition has cardiovascular difficulties, cardiologists can help with the management of the symptoms.

• In order to reach the highest possible potential, it is crucial that the symptoms are diagnosed earlier and the child is provided the best care. In many cases, speech therapy, sign language, and physical therapy have proved to be very beneficial.

• If any severe symptoms require emergency care, surgery is performed to manage them.

Conclusion

Being a rare disorder, sometimes it is difficult to manage the multi-system involvement of the disorder. However, the survival rate of the condition is very good, and it is known that patients with these symptoms can survive for a longer time. Only the symptoms need to be managed along with regular follow-ups.