Cat eye syndrome

Cat eye syndrome
Synonyms	Schmid–Fraccaro syndrome
Pronounce	N/A
Specialty	N/A
Symptoms	Coloboma, anal atresia, heart defects, kidney malformations
Complications	Developmental delay, intellectual disability
Onset	Congenital
Duration	Lifelong
Types	N/A
Causes	Chromosomal abnormality
Risks	Genetic predisposition
Diagnosis	Karyotype, genetic testing
Differential diagnosis	Down syndrome, Turner syndrome
Prevention	N/A
Treatment	Symptomatic management, surgery
Medication	N/A
Prognosis	Variable, depends on severity of symptoms
Frequency	Rare, estimated 1 in 50,000 to 150,000 live births
Deaths	N/A

A rare chromosomal disorder

Cat eye syndrome (CES), also known as Schmid-Fraccaro syndrome, is a rare genetic disorder characterized by the presence of a small extra chromosome derived from chromosome 22. This condition is named for the distinctive eye appearance that some affected individuals exhibit, although not all individuals with the syndrome have this feature.

Genetics

Cat eye syndrome is caused by the presence of an extra chromosome fragment, known as a supernumerary marker chromosome, which contains duplicated material from chromosome 22. This extra genetic material can lead to a variety of developmental abnormalities. The syndrome is typically sporadic, meaning it usually occurs as a new mutation and is not inherited from a parent.

Clinical Features

The clinical presentation of cat eye syndrome can vary widely among affected individuals. Common features include:

• Coloboma of the iris, which gives the eyes a "cat-like" appearance.
• Anal atresia, a condition where the opening to the anus is missing or blocked.
• Ear abnormalities, such as preauricular tags or pits.
• Congenital heart defects, which may include tetralogy of Fallot or other structural heart anomalies.
• Renal malformations, which can affect kidney function.
• Skeletal abnormalities, such as scoliosis or limb defects.

Diagnosis

Diagnosis of cat eye syndrome is typically made through chromosomal analysis, such as karyotyping or fluorescence in situ hybridization (FISH), which can identify the presence of the extra chromosome 22 material. Genetic counseling is recommended for affected families.

Management

There is no cure for cat eye syndrome, and treatment is symptomatic and supportive. Management may involve:

• Surgical correction of anatomical abnormalities, such as anal atresia or heart defects.
• Regular monitoring and treatment of kidney function.
• Developmental support and educational interventions for children with learning difficulties.
• Regular ophthalmologic evaluations for eye abnormalities.

Prognosis

The prognosis for individuals with cat eye syndrome varies depending on the severity of symptoms and the presence of associated anomalies. With appropriate medical care and interventions, many individuals can lead relatively normal lives.

Related pages

• Chromosome 22
• Genetic disorder
• Coloboma
• Congenital heart defect