Natural History Study of Patients with HPDL Mutations

A Patient Registry and Natural History Study of Patients with Biallelic HPDL Mutations

This study uses medical records that allow retrospective data extraction of clinical manifestation to assess the natural history of HPDL mutations

A novel mitochondrial disease arises from mutations in HPDL, which codes for 4-hydroxyphenylpyruvate dioxygenase-like protein. The main purpose of this study is to establish a patient registry to gather medical data from consenting HPDL mutation patients worldwide. From longitudinal data, we will be able to figure out the natural history of the disease, and genotype-phenotype correlation. Dry blood spots will be collected to develop biomarkers to understand the disease better.

Inclusion Criteria:

• Any individuals diagnosed with HPDL variants

• Clinical diagnosis can include:

  • HPDL-related hereditary spastic paraplegia (HSP)
  • HPDL-related neonatal mitochondrial encephalopathy
  • Spastic paraplegia -83 (SPG83)
  • Neurodevelopmental disorder with progressive spasticity and brain white matter abnormalities (NEDSWMA)

Exclusion Criteria:

• Any known genetic abnormality (other than HPDL mutation)
• Any condition that, in the opinion of the Site Investigator, could put the participant at undue risk and/or would ultimately prevent the completion of study procedures