Definition:
Jansky-Bielschowsky/Late Infantile CLN2/TPP1 disorder is part of a group of progressive degenerative neurometabolic disorders known as the neuronal ceroid lipofuscinoses (NCLs). The NCLs are characterized by an abnormal accumulation of lipopigaments, which are subtances combined of fats and proteins within the brain’s nerve cells, eyes, skin, muscle, and other tissues throughout the body.

Skin biopsies in CLN2 show characteristic curvilinear bodies. The cause of CLN2 is mutations in the CLN 2 gene which lead to deficient activity of the TPP1 enzyme.

The disorder causes nerve cells, found in the brain, retina, and central nervous system, to die. The reason for this remains unknown.

It is estimated that the NCLs affect two to four of every 100,000 live births in the United States.

Symptoms:
Symptoms of Jansky-Bielschowsky/Late Infantile CLN2/TPP1 disorder begin between two and four years of age. The loss of muscle coordinatio, and progressive mental deterioration are symptoms typical of this disorder. Seizures are also a common symptom.

Inheritance Pattern:
Jansky-Bielschowsky/Late Infantile CLN2/TPP1 disorder is an autosomal recessive disorder.

Life Expectancy:
Life Expectancy for Jansky-Bielschowsky/Late Infantile CLN2/TPP1 disorder is between eight and 12 years of age.

Diagnosis and Testing:
CLN2 is diagnosed by showing corresponding mutations in the CLN2 gene and deficient activity of the TPP1 enzyme.

Treatment:
There is no cure for Jansky-Bielschowsky/Late Infantile CLN2/TPP1 disorder. Treatment is limited to reducing or controlling the symptoms of this disorder, by regular consultation with neurologists, ophthalmologists and genetic counselors. Neurologists are able to help control seizures or nervous system complications. An ophthalmologist can monitor vision loss, and physical and occupational therapists can assist the affected individual in maintaining muscle movement and reducing muscle discomfort.