Childhood-onset restless legs syndrome: clinical and genetic features of 22 families.
Restless legs syndrome (RLS) is a sensory-motor disorder that is underdiagnosed in children and often misclassified as attention deficit hyperactivity disorder. Five different gene loci (RLS1-5) and three susceptibility loci have been identified in adult-onset RLS. We included 23 children with RLS (age at onset < or =14 years) from 22 families. In 14 families, we performed linkage and genotype analyses. Of the 23 RLS patients, only seven (30.4%) were admitted for a suspected diagnosis of RLS. Five patients had a retrospectively established onset at an age as early as 1 year. The most frequent complaint in patients were sleep problems (21 of 23; 91%) resulting in fatigue in 14 children (60.9%). Twelve of the 19 tested cases (63.2%) exhibited an index of periodic limb movements in sleep greater than 5. Dopaminergic therapy was successful in 12 of 14 treated patients (85.7%). Family history for RLS was positive in 20 of 23 children (87.0%) and compatible with an autosomal dominant inheritance pattern. Linkage analysis excluded all five loci in two families. A trend for an association at two of the three reported susceptibility regions was observed. RLS symptoms can occur in early childhood. The positive family history suggests a genetic cause in most families with at least one additional RLS gene locus.
Muhle
Hiltrud
H
Department of Neuropediatrics, University of Kiel, Kiel, Germany. muhle@pedneuro.uni-kiel.de
Neumann
Anja
A
Lohmann-Hedrich
Katja
K
Lohnau
Thora
T
Lu
Yang
Y
Winkler
Susen
S
Waltz
Stephan
S
Fischenbeck
Anke
A
Kramer
Patricia L
PL
Klein
Christine
C
Stephani
Ulrich
U
D000293:Adolescent; D017668:Age of Onset; D000483:Alleles; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis; D002648:Child; D002675:Child, Preschool; D002869:Chromosome Aberrations; D002874:Chromosome Mapping; D003937:Diagnosis, Differential; D005260:Female; D005799:Genes, Dominant / Q000235:genetics; D020022:Genetic Predisposition to Disease / Q000235:genetics; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D007223:Infant; D008297:Male; D018895:Microsatellite Repeats; D010375:Pedigree; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D012148:Restless Legs Syndrome / Q000175:diagnosis / Q000235:genetics*