3C syndrome

A rare genetic disorder

3C syndrome, also known as cranio-cerebello-cardiac dysplasia, is a rare genetic disorder characterized by craniofacial abnormalities, cerebellar malformations, and congenital heart defects. It is inherited in an autosomal recessive pattern.

Presentation

Individuals with 3C syndrome typically present with a combination of distinctive craniofacial features, neurological abnormalities, and heart defects. Common craniofacial features include a prominent forehead, a broad nasal bridge, and hypertelorism (widely spaced eyes). Neurological features often involve cerebellar hypoplasia, which can lead to ataxia and developmental delays. Cardiac anomalies may include ventricular septal defects and other structural heart defects.

Genetics

3C syndrome is caused by mutations in the KIAA0196 gene, which is located on chromosome 8. This gene is responsible for encoding a protein involved in cellular processes such as endocytosis and vesicle trafficking. The disorder follows an autosomal recessive inheritance pattern, meaning that an affected individual must inherit two copies of the mutated gene, one from each parent.

Diagram of autosomal recessive inheritance

Diagnosis

Diagnosis of 3C syndrome is based on clinical evaluation, identification of characteristic features, and genetic testing to confirm mutations in the KIAA0196 gene. Prenatal diagnosis may be possible through genetic testing if there is a known family history of the disorder.

Management

Management of 3C syndrome is supportive and symptomatic. It may involve a multidisciplinary approach including pediatricians, cardiologists, neurologists, and genetic counselors. Surgical intervention may be required for certain cardiac defects, and physical therapy can help manage motor difficulties associated with cerebellar hypoplasia.

Prognosis

The prognosis for individuals with 3C syndrome varies depending on the severity of the symptoms and the presence of life-threatening cardiac defects. Early intervention and supportive care can improve quality of life and developmental outcomes.

Related pages

• Genetic disorder
• Cerebellar hypoplasia
• Congenital heart defect
• Autosomal recessive disorder

Gallery

• 
  Expression pattern of KIAA0196

• 
•