Kufs disease is an inherited neurodegenerative disorder known as adult neuronal ceroid lipofuscinosis (ANCL). It is caused by the accumulation of lipopigments in the nerve cells resulting in progressive atrophy of certain regions of the brain characterized by cognitive and motor deficits.
Symptoms of Kufs disease may onset anywhere between adolescence and adulthood. However, signs and symptoms typically onset about 30 years of age. Common presenting features include ataxia, myoclonus, parkinsonism, chorea, spasticity, and cognitive impairment.
There are two subtypes of Kufs disease: Type A and Type B [1]. The symptoms of the subtypes often overlap and make it difficult to make a distinction between the two subtypes of Kufs disease [2] [3]. Regardless of the subtype, symptoms are progressive and worsen over time.
The diagnosis of Kufs disease is based on the recognition of symptoms, a patient and family history, psychiatric evaluation, clinical testing including a neurologic exam and specialized tests (e.g., enzyme assays and molecular genetic tests). Since Kufs disease is inherited, the patient should be asked about family members who may have had similar symptoms.
Enzyme assays can be useful for making a diagnosis. For example, Kufs disease is characterized by reduced enzyme activity of certain substances such as cathepsin F, the enzyme produced by the CTSF gene [7]. Recent studies have shown an association between certain enzyme defects and 8 primary genetic forms of Kufs disease [8].
Microscopic exam (using an electron microscope) of skin or tissue biopsies may show the buildup of storage material within the affected tissue. Lipopigment inclusions, while most frequently described in neuron cytoplasm, have also been found in vascular smooth muscle cells, Schwann cells and sweat gland epithelial cells. In Kufs disease, the deposits display a fingerprint-type pattern [9].
Molecular genetic testing permits a diagnosis of Kufs disease. It can reveal mutations in genes known to cause the various subtypes (e.g., CLN/CLN13 or PPT1 genes). It is important to note that a lack of mutations in these genes does not exclude the diagnosis of the disease since Kufs disease may be a result of genetic mutations in other, undocumented or unknown, genes [10].
An electroencephalogram can be used to examine the frequency and type of epileptic seizures.
Magnetic resonance imaging (MRI) scan may facilitate diagnosis of Kufs disease. During the early stages of behavioral changes associated with the disease, MRI images show hyperintensities in the white matter that indicate volume reduction of the corpus callosum [10].