Cri-du-chat Syndrome

Original Editor - Swati singh

Top Contributors - Swati Singh  

Introduction

Cri-du-chat syndrome (CdCS) is a rare genetic disorder first identified in 1963 by Dr. Jérôme Lejeune. The name, meaning "cry of the cat" in French, refers to affected infants' characteristic, high-pitched, cat-like cry. This condition is caused by a deletion of genetic material on the short arm of chromosome 5, specifically in the region known as 5p.

The deletion size can vary, ranging from a small segment like band 5p15.2 to, in some cases, the entire short arm. While most cases of CdCS occur due to new (de novo) mutations, approximately 12% are inherited through unbalanced chromosomal rearrangements, such as translocations or pericentric inversions, from a parent. Understanding the genetic basis and inheritance patterns of CdCS is essential for accurate diagnosis, counselling, and management.

Signs and symptoms

The clinical presentation varies among individuals, influenced by the size and location of the chromosomal deletion.

Distinctive Cry

A hallmark feature of this syndrome is a high-pitched, cat-like cry observed in newborns, attributed to abnormalities in the larynx and nervous system. This distinctive cry typically diminishes as the child grows older.

Craniofacial Features

Infants with Cri du Chat syndrome often exhibit distinctive facial characteristics, including a small head (microcephaly), a round face, widely spaced eyes (hypertelorism), a broad nasal bridge, low-set ears, a small jaw (micrognathia), and a short philtrum. Some may also present with cleft palate or lip, and a bifid uvula.

Growth and Developmental Delays

Affected individuals commonly experience low birth weight and growth deficiencies. Hypotonia (reduced muscle tone) is prevalent in infancy, potentially progressing to hypertonia (increased muscle tone) with age. Developmental milestones such as head control, sitting, and walking are often delayed. Speech and language development is typically impaired, with receptive language skills often surpassing expressive abilities. Intellectual disability ranges from moderate to severe.

Behavioral Characteristics

Children with Cri du Chat syndrome may display behavioural issues, including hyperactivity, self-injurious behaviours, repetitive movements, and obsessive attachment to objects. Despite these challenges, many exhibit a gentle and affectionate demeanour.

Additional Physical Anomalies

Other associated features can include scoliosis (curvature of the spine), congenital heart defects, feeding difficulties, respiratory issues, recurrent ear infections leading to hearing loss, vision problems such as strabismus, and genital anomalies like cryptorchidism or hypospadias. Skeletal anomalies such as clinodactyly (curved fingers) or clubfoot may also be present.

Age-Related Changes

As individuals age, facial features may evolve from a round to a more elongated appearance. Muscle tone abnormalities may shift, and behavioural challenges can persist or intensify. Early intervention and supportive therapies are crucial in managing symptoms and enhancing quality of life.

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