5p- Syndrome (Cri du Chat Syndrome)

Description

Cri du Chat Syndrome, also known as 5p- syndrome, is a rare genetic disorder characterized by a distinctive high-pitched, cat-like cry in infants. This condition is caused by a deletion of genetic material on the short arm of chromosome 5. While the severity of symptoms can vary, individuals with Cri du Chat Syndrome often face developmental delays, intellectual disabilities, and distinctive facial features. This blog post provides comprehensive information about this syndrome, including its signs and symptoms, causes, diagnosis, management, and strategies for thriving.

Genes Involved

Cri du Chat Syndrome is caused by a deletion of genetic material on the short arm of chromosome 5. This deletion can vary in size and location, but it typically involves several genes, including:

TERT: This gene is involved in telomere maintenance, which plays a role in cell division and aging.
CTNND2: This gene is involved in cell adhesion and may be associated with brain development.
SNRPN: This gene is involved in the production of a protein that plays a role in the nervous system.
Other Genes: The exact genes involved in Cri du Chat Syndrome can vary depending on the size and location of the deletion.

Recognizing the Signs and Symptoms

The most notable symptom of Cri du Chat Syndrome is the distinctive cat-like cry in infants, often described as high-pitched and shrill. This cry, which usually fades as the child gets older, results from abnormalities in the larynx and vocal cords. Other common signs and symptoms may include:

Distinctive Facial Features: Individuals with Cri du Chat Syndrome often have specific facial characteristics such as a small head (microcephaly), widely spaced eyes (hypertelorism), a low-set nose bridge, and a small jaw (micrognathia).
Developmental Delays: Cri du Chat Syndrome can lead to developmental delays in various areas, including motor skills, speech, and cognitive development.
Intellectual Disabilities: The severity of intellectual disability can vary greatly among individuals with Cri du Chat Syndrome. Some may have mild delays, while others may have more significant cognitive challenges.
Heart Defects: Congenital heart defects, such as a ventricular septal defect or patent ductus arteriosus, can occur in some individuals.
Feeding Difficulties: Infants with Cri du Chat Syndrome may experience feeding problems due to weak muscle tone and difficulty sucking.
Sleep Apnea: Obstructive sleep apnea can occur due to abnormalities in the facial structure.
Gastrointestinal Issues: Gastrointestinal problems, such as constipation or reflux, can be common.
Behavioral Challenges: Some individuals with Cri du Chat Syndrome may experience behavioral difficulties, such as hyperactivity, aggression, or attention deficit hyperactivity disorder (ADHD).
Other Potential Complications: Other potential complications may include hypotonia (decreased muscle tone), seizures, and hearing loss.

Causes

Cri du Chat Syndrome is a chromosomal abnormality that occurs during the formation of egg or sperm cells, or in the early stages of embryonic development. The deletion of genetic material on chromosome 5 is a random event and is not usually inherited from a parent. It is considered a de novo mutation.

Inheritance/recurrence risk

Cri du Chat Syndrome is typically not inherited from a parent. It is usually a sporadic event, meaning it occurs randomly in an individual without any family history of the condition. The risk of recurrence in future pregnancies is generally low, but it is important to consult with a genetic counselor for personalized advice.

WES Whole Exome Sequencing