The study objective is to evaluate the efficacy of L-serine in subjects with hereditary sensory neuropathy type 1 (HSAN1). Hereditary sensory and autonomic neuropathy type I (HSAN1) is a progressive and debilitating illness for which currently no treatment exists. Two novel deoxysphingoid bases (DSB) were recently identified that accumulate in plasma of HSAN1 patients and mutant transgenic HSAN1 mice. The disease is caused by missense mutations in the SPTLC1 gene encoding a subunit of the enzyme serine palmitoyltransferase (SPT). In normal circumstances the SPT enzyme catalyzes the reaction of palmitoyl-CoA with serine to form sphinganine. The two newly identified DSB, deoxysphinganine and deoxymethylsphinganine, arise from condensation of palmitoyl-CoA with alanine and glycine respectively, suggesting that HSAN1 mutations alter amino acid selectivity of SPT. In support of this hypothesis it is shown that levels of DSB in humans and mice can be lowered by supplementation with the enzyme's normal substrate, serine. In this randomized, double-blind, placebo-controlled study, 20 research participants with HSAN1 will be enrolled with 10 subjects assigned to L-serine (400mg/kg/d) and 10 assigned to placebo who are each treated for 24 months. The progression of HSAN1 will be measured by the change in an established clinical rating scale and measures of intraepidermal nerve fiber density (IENFD) on skin biopsy. The percentage of failures [clinical decline of > 1 point on Charcot Marie Tooth Neurological Score (CMTNS) or > 30% decrease in IENFD] will be assessed at 6 month intervals. If patients in the placebo arm fail, they will be switched to L-serine. There will be an interim analysis at 12 and 18 months to assess for efficacy and futility, and accordingly the study will be stopped or continued.

Public Health Relevance

In hereditary and sensory autonomic neuropathy type 1 (HSAN1) we recently discovered the accumulation of two neurotoxic sphingolipids. In the current proposal we will perform a randomized, double-blind, placebo-controlled study of L- serine supplementation to correct the biochemistry and neurological disease in HSAN1.

Agency
National Institute of Health (NIH)
Institute
Food and Drug Administration (FDA)
Type
Research Project (R01)
Project #
4R01FD004127-03
Application #
8900793
Study Section
Special Emphasis Panel (ZFD1)
Project Start
2012-09-14
Project End
2017-08-31
Budget Start
2015-09-01
Budget End
2016-08-31
Support Year
3
Fiscal Year
2015
Total Cost
Indirect Cost
Name
Massachusetts General Hospital
Department
Type
DUNS #
073130411
City
Boston
State
MA
Country
United States
Zip Code
White, Matthew A; Kim, Eosu; Duffy, Amanda et al. (2018) TDP-43 gains function due to perturbed autoregulation in a Tardbp knock-in mouse model of ALS-FTD. Nat Neurosci 21:552-563
Ahrens-Nicklas, Rebecca; Schlotawa, Lars; Ballabio, Andrea et al. (2018) Complex care of individuals with multiple sulfatase deficiency: Clinical cases and consensus statement. Mol Genet Metab 123:337-346
Fil, Daniel; DeLoach, Abigail; Yadav, Shilpi et al. (2017) Mutant Profilin1 transgenic mice recapitulate cardinal features of motor neuron disease. Hum Mol Genet 26:686-701
Eichler, Florian S; Li, Jiankang; Guo, Yiran et al. (2016) CSF1R mosaicism in a family with hereditary diffuse leukoencephalopathy with spheroids. Brain 139:1666-72
Henninger, Nils; Bouley, James; Sikoglu, Elif M et al. (2016) Attenuated traumatic axonal injury and improved functional outcome after traumatic brain injury in mice lacking Sarm1. Brain 139:1094-105
Peters, Owen M; Cabrera, Gabriela Toro; Tran, Helene et al. (2015) Human C9ORF72 Hexanucleotide Expansion Reproduces RNA Foci and Dipeptide Repeat Proteins but Not Neurodegeneration in BAC Transgenic Mice. Neuron 88:902-909
Fridman, Vera; Oaklander, Anne Louise; David, William S et al. (2015) Natural history and biomarkers in hereditary sensory neuropathy type 1. Muscle Nerve 51:489-95
Sreedharan, Jemeen; Brown Jr, Robert H (2013) Amyotrophic lateral sclerosis: Problems and prospects. Ann Neurol 74:309-16