Have you ever heard of a natural history study? In short, a natural history study studies people who have, or are at risk of developing, a specific medical condition; this is especially helpful for those with rare conditions. During the natural history study, researchers collect a range of information—symptoms, test results, biomarkers, outcomes—from the onset of a disease until its resolution. 

In a recent news release, biotech and collaborative company Phoenix Nest shared that it would be launching ALL-127, a natural history study focused on a subset of Sanfilippo syndrome called Sanfilippo syndrome type D. Phoenix Nest was founded based on parent and caregiver love for their children affected by Sanfilippo syndrome. The company’s mission is to develop medications to help these children. 

Currently, no FDA-approved treatment options exist for children with Sanfilippo syndrome type D. Through this study, Phoenix Nest hopes to identify potential trial endpoints while also deepening the understanding of what this disease is. Data from this study could inform future research. For now, the study will take place at Columbia University Irving Medical Center. 

During the study, patients will visit the Medical Center three times. For the remainder of the study, caregivers will tape several different tasks using the RARE app. This will help researchers and doctors gain a better understanding of how Sanfilippo syndrome affects daily living. Through this study, researchers hope to learn more about mobility and cognition. 

A Basic Overview of Sanfilippo Syndrome (MPS III)

Sanfilippo syndrome, or mucopolysaccharidosis type III (MPS III), is a rare inherited lysosomal storage disorder. There are four subtypes of Sanfilippo syndrome (A, B, C, and D), with type D being the rarest form. In each case, the child has a genetic variation which impairs the body’s ability to break down heparan sulfate, a type of sugar molecule. As a result, the heparan sulfate accumulates in cells, causing damage. Symptoms of Sanfilippo syndrome typically appear within one year of birth, with cognitive and learning decline occurring between ages 2 and 6. However, symptoms may appear within the entire spectrum of early childhood. Potential symptoms can include:

• Umbilical or inguinal hernias
• Developmental delays or developmental regression
• Enlarged liver and/or spleen
• Diarrhea
• Delayed speech
• Impaired hearing or vision
• Behavioral issues
• Frequent respiratory infections
• Macrocephaly (a larger than average head size)
• Macroglossia (an enlarged tongue) 
• Sleep disruptions or difficulties
• Stiff joints that may not extend fully
• Seizures