Knobloch syndrome

Knobloch syndrome is a rare genetic disorder characterized by a combination of ocular and cranial abnormalities. It is named after the German ophthalmologist Werner Knobloch, who first described the condition. The syndrome is primarily associated with mutations in the COL18A1 gene, which encodes the protein collagen XVIII.

Clinical Features

Individuals with Knobloch syndrome typically present with a range of symptoms, including:

• Severe myopia (nearsightedness)
• Retinal detachment
• Vitreoretinal degeneration
• Macular degeneration
• Cranial abnormalities, such as occipital encephalocele or microcephaly
• Intellectual disability in some cases

Genetics

Knobloch syndrome is inherited in an autosomal recessive manner. This means that an individual must inherit two copies of the mutated gene, one from each parent, to manifest the disorder. The primary gene implicated in Knobloch syndrome is COL18A1, which is located on chromosome 21.

Diagnosis

Diagnosis of Knobloch syndrome is based on clinical evaluation, family history, and genetic testing. Ophthalmologic examination is crucial for identifying the characteristic eye abnormalities. Neuroimaging techniques, such as MRI or CT scan, may be used to detect cranial defects.

Management

There is no cure for Knobloch syndrome, and treatment is primarily supportive. Management strategies may include:

• Regular ophthalmologic evaluations to monitor and treat eye conditions
• Surgical intervention for retinal detachment
• Special education services for individuals with intellectual disabilities
• Genetic counseling for affected families

Epidemiology

Knobloch syndrome is extremely rare, with only a few hundred cases reported worldwide. The exact prevalence is unknown due to the rarity of the condition and potential underdiagnosis.

See Also

• COL18A1
• Retinal detachment
• Myopia
• Autosomal recessive
• Genetic counseling

External Links

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