Affiliations: School of Biosciences, University of Birmingham,
Birmingham, UK | Department of Neurogenetics Kennedy Krieger Institute
Baltimore, USA | Institute of Pediatric Research, Rikshospitale, Oslo,
Norway
Note: [] Correspondence: Dr. Rosemary Waring, School of Biosciences,
University of Birmingham, Birmingham B15 2TT, UK. Tel.: +44 121 414 5421; Fax:
+44 121 414 5925; E-mail: [email protected]
Abstract: Although mutations in the MECP2 gene are associated with many cases
of Rett syndrome (RS), the phenotype remains unexplained. At least in the early
stages, RS and autism have common features; urinary analysis of autistic
children has shown an abnormal profile of excretion of sulphur-containing
anions, with high levels of sulphite, sulphate and thiosulphate and low values
for thiocyanate ions. These parameters were therefore studied in an RS
population. Levels of urinary peptides, protein, cysteine, free sulphate,
conjugated sulphate, sulphite, thiosulphate and thiocyanate were determined in
female RS patients (n=21) and in controls
n=21), using standard methods. The urinary volumes were
adjusted to standard creatinine levels (200 nmol/mL). Children with RS had
higher urinary peptides and protein excretion. Free sulphate values and total
sulphate excretion were higher in RS (P<0.001) than in
controls. Cysteine, sulphite and thiosulphate excretion were elevated
(P<0.001) while thiocyanate excretion was greatly reduced
(P<0.001). These results are consistent with reduced
expression or activity of the enzyme rhodanese (thiosulphate cyanide
sulphurtransferase). Other mutation(s) in genes involved in metabolism of
sulphur anions may also contribute to the RS phenotype.
Keywords: Rett syndrome, sulphur anions, metabolism, rhodanese
