Definition:
Santavuori-Haltia/Infantile CLN1/PPT Disease 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 within other tissues throughout the body.

Examination of cells under the electron microscope shows accumulation of pigments in the form of granular osmoiphilic deposits (GRODs), also known as “Finnish snowballs.” This appearance is characteristic for this form of neuronal ceroid lipofuscinoses.

NCL I is known to result from deficient activity of an enzyme called palmitoyl—protein thioesterase-1 (PPT-10). The gene coding for this enzyme has been named CLN1. Mutations can be demonstrated and are useful in confirming the diagnosis and in performing prenatal diagnosis.

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

Symptoms:
Symptoms of Santavuori-Haltia/Infantile CLN1/PPT Disease begin between six months and 19 months of age. During ages of six to 19 months, a delay in mental and muscular activities appears at the same time when the affected child begins to lose the mental and physical skills he/she had acquired. A small head, seizures, an inability to coordinate voluntary muscular movements, decreasing muscle tone, muscle spasms, and visual impairments are additional symptoms. As neurological complication progress, immobility, spastic and involuntary movements, and a lack of response may also occur.

Inheritance Pattern:
Santavuori-Haltia/Infantile CLN1/PPT disorder is an autosomal recessive disorder.

Life Expectancy:
Life Expectancy for Santavuori-Haltia/Infantile CLN1/PPT disorder is five years of age or younger.

Diagnosis and Testing:
The diagnosis of Santayouri-Haltia Disease is made by demonstrating reduced activity of PPT and by showing corresponding mutations in the CLN1 gene. Characteristic changes may be shown in skin biopsy on electron microscopy and the electro-retina-gram. An MRI scan of the brain typically shows severe atrophy of the cerebral hemispheres and cerebellum.

Treatment:
There is no cure for Santavuori-Haltia/Infantile CLN1/PPT disorder. Treatment is limited to reducing or controlling the symptoms of this disorder by routine consultation with the patient’s neurologists, ophthalmologists and genetic counselors. Neurologists may assist in keeping seizures or nervous system complications under control. An ophthalmologist can monitor vision loss, and physical and occupational therapists can help the affected individual maintain muscle movement and reduce muscle discomfort.