PPT1

PPT1 or Palmitoyl-Protein Thioesterase 1 is an enzyme that is encoded by the PPT1 gene in humans. This enzyme is involved in the catabolism of lipid-modified proteins during lysosomal degradation. Mutations in the PPT1 gene are associated with a form of neuronal ceroid lipofuscinosis (NCL) known as Infantile Neuronal Ceroid Lipofuscinosis (INCL) or Santavuori-Haltia disease.

Function

PPT1 is a small glycoprotein enzyme that removes long fatty acid chains such as palmitate from modified cysteine residues in proteins or peptides during lysosomal degradation. This process is essential for the normal functioning of cells. The enzyme is most active in neurons, especially in the cerebellum, cortex, and retina.

Clinical Significance

Mutations in the PPT1 gene cause a rare and fatal neurodegenerative disease known as Infantile Neuronal Ceroid Lipofuscinosis (INCL) or Santavuori-Haltia disease. This disease is characterized by progressive loss of vision, mental and motor deterioration, seizures, and premature death, usually within the first decade of life.

Diagnosis and Treatment

Diagnosis of INCL is based on clinical symptoms, enzymatic analysis of white blood cells or skin fibroblasts, and confirmed by genetic testing of the PPT1 gene. Currently, there is no cure for INCL. Treatment is symptomatic and supportive, and may include anticonvulsant medication to control seizures, physical therapy to manage loss of motor skills, and other interventions to improve quality of life.

Research

Research is ongoing to better understand the function of PPT1 and the pathogenesis of INCL. Experimental therapies such as enzyme replacement therapy and gene therapy are being explored.