Autosomal dominant GTP cyclohydrolase i (AD GCH 1) deficiency (Segawa disease, dystonia 5; DYT 5)
Segawa, M.
Chang Gung Medical Journal 32(1): 1-11
2009
ISSN/ISBN: 2072-0939 PMID: 19292934 Document Number: 629018
Autosomal dominant GTP cyclohydrolase I (AD GCH 1) deficiency (Segawa disease) is an autosomal dominant dopa responsive dystonia caused by heterozygous mutation of the GCH 1 gene located on 14q22.1-q22.2. Although a number of mutations have been reported, the change remains highly stable within families, and causes a decrease in the tyrosine hydroxylase protein at the nigrostriatal (NS)-dopamine (DA) neuron terminal. In addition, decreased tetrahydrobiopterin levels early in the development affect DA receptors age-dependently, and produce a spectrum of specific symptoms attributed to neuronal changes traced to processes in the development of the NS-DA neuron, related striatal projection neurons, and the output projection of the basal ganglia.