NCT02924935

Histidine Therapy: A Project to Treat HARS Deficiency

• Status: Unknown
• Phase: Phase 2 / Phase 3
• Study type: Interventional
• Enrollment: 14 (actual)
• Sponsor: London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's · Academic / Other
• Sex: All
• Age: —
• Healthy volunteers: Not accepted

Summary

This study evaluates the role of histidine in patients with HARS Syndrome. Children with HARS Syndrome will receive oral nutritional supplementation with histidine at a dose which will be increased in the event of acute febrile illness. Vision, hearing and plasma biomarkers will be monitored throughout the study period.

Detailed description

HARS syndrome is a progressive degenerative disease affecting eyesight and hearing caused by a mutation in the HARS gene which codes for an enzyme involved in protein synthesis. HARS syndrome has been exclusively found in the Old Order Amish communities in Southwestern Ontario and in Pennsylvania. Children with this disorder initially have normal vision and hearing, but with a febrile illness, can have a sudden loss of vision and hearing, as well as visual hallucinations. There is some evidence that vision loss progresses, albeit at a slower rate, even without a febrile incident. In more severe cases, fluid accumulates in the lungs (acute respiratory distress syndrome or ARDS) which can cause a drop in oxygen levels and sometimes death. There is currently no specific treatment for HARS syndrome, apart from supportive care. Anecdotal evidence of an adult with HARS syndrome who was treated with the amino acid L-histidine suggests that there was an improvement in vision, however there were no baseline objective measurements of vision prior to the use of histidine. We have designed a pilot project in which histidine will be given to children with HARS for 6 months. Investigators hypothesize that the histidine will be well tolerated and easily administered, without side effects. Investigators will monitor vision, hearing and bloodwork to determine if there is any change during the course of treatment. As well, investigators plan to administer increased doses of histidine during acute illnesses, hoping to prevent deterioration in breathing due to ARDS. The results of this initial pilot project may pave the way for a longer term study of the use of histidine.

Conditions

• HARS Syndrome

Interventions

Type	Name	Description
DIETARY_SUPPLEMENT	L-Histidine	L-Histidine in 500mg capsules taken at a dose of 50mg/kg to maintain high-normal serum histidine levels

Timeline

• Start date: 2018-08-01
• Primary completion: 2021-10-31
• Completion: 2022-12-31
• First posted: 2016-10-05
• Last updated: 2022-06-10

Locations

1 site across 1 country: Canada

Regulatory

• FDA-regulated drug study