title: Atypical presentation of dopa-responsive dystonia: generalized hypotonia and proximal weakness.
abstract: Dopa-responsive dystonia (DRD) is an autosomal dominant disorder typically presenting as dystonia with diurnal variability. Described is an 8-year-old boy who had had waddling gait, generalized hypotonia, and proximal weakness since early childhood. He responded well to low-dose L-dopa. He had a point mutation of the GTP cyclohydrolase I gene. The patient's father and sister had the same mutation but did not have proximal weakness. GTP cyclohydrolase I deficiency can present with hypotonia and weakness.
authors.affiliation: Department of Paediatrics, Caritas Medical Centre, Hong Kong, China. ck_kong@hotmail.com
authors.forename: C K
authors.initials: CK
authors.lastname: Kong
authors.forename: C H
authors.initials: CH
authors.lastname: Ko
authors.forename: S F
authors.initials: SF
authors.lastname: Tong
authors.forename: C W
authors.initials: CW
authors.lastname: Lam
mesh_terms: D002230:Carbidopa / Q000627:therapeutic use*; D002648:Child; D002869:Chromosome Aberrations / Q000235:genetics*; D025063:Chromosome Disorders; D002940:Circadian Rhythm / Q000502:physiology; D004338:Drug Combinations; D020821:Dystonic Disorders / Q000175:diagnosis* / Q000188:drug therapy / Q000235:genetics; D006136:GTP Cyclohydrolase / Q000235:genetics; D005684:Gait / Q000187:drug effects; D005799:Genes, Dominant / Q000235:genetics*; D006801:Humans; D007980:Levodopa / Q000627:therapeutic use*; D008297:Male; D009123:Muscle Hypotonia / Q000175:diagnosis* / Q000188:drug therapy / Q000235:genetics; D018908:Muscle Weakness / Q000175:diagnosis* / Q000188:drug therapy / Q000235:genetics; D009460:Neurologic Examination; D017354:Point Mutation; D016896:Treatment Outcome
chemical_list: D004338:Drug Combinations; C009265:carbidopa, levodopa drug combination; D007980:Levodopa; D006136:GTP Cyclohydrolase; D002230:Carbidopa