There is one clinical trial.
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.
Inclusion Criteria: 1. Have molecularly confirmed HARS syndrome (Y454S homozygous). --- Y454S ---
Description: Changes from baseline eye exam
Measure: Visual acuity maintenance or improvement Time: 2 yearsDescription: Changes from baseline electroretinography
Measure: Visual acuity maintenance or improvement Time: 2 yearsDescription: Changes from baseline ocular coherence tomography
Measure: Visual acuity maintenance or improvement Time: 2 yearsDescription: Changes from baseline auditory brainstem response
Measure: Auditory ability maintenance or improvement Time: 2 yearsDescription: Changes from baseline autoacoustic emissions
Measure: Auditory ability maintenance or improvement Time: 2 yearsDescription: Changes from baseline routine ear exam
Measure: Auditory ability maintenance or improvement Time: 2 yearsDescription: Changes from baseline audiometry
Measure: Auditory ability maintenance or improvement Time: 2 yearsDescription: Measured by length of hospital stay
Measure: Changes in severity of acute febrile illness Time: 2 yearsDescription: Measured by requirement for intensive care unit transfer
Measure: Changes in severity of acute febrile illness Time: 2 yearsDescription: Measured by number of hospitalizations
Measure: Changes in severity of acute febrile illness Time: 2 yearsDescription: Changes to inflammatory markers, HARS protein, HARS antibodies, Amino acid levels and biochemical markers as a result of histidine therapy
Measure: Biomarker Changes Time: 2 yearsDescription: Does histidine supplementation result in increased plasma histidine levels
Measure: Plasma level maintenance Time: 1 month