Vitamin D deficiency in Serbian patients with Rett syndrome.

INTRODUCTION: Rett syndrome (RTT) is a severe neurodevelopmental disorder. Bone manifestations of RTT include osteopenia and fractures. Studies addressing serum vitamin D levels in patients with RTT are scarce. GOALS: The goals of this study were (1) to determine the prevalence of vitamin D deficiency in patients with RTT, (2) to compare serum vitamin D levels between patients with RTT and those with other neurological diseases, and (3) to explore the correlation between demographic and clinical characteristics of patients with RTT and vitamin D levels. METHODS: Demographic and clinical characteristics included age, body mass index Z-score, mutation status, clinical severity score, presence of epilepsy, number of antiepileptic drugs, history of fractures, scoliosis, and ambulation ability. Laboratory parameters included serum 25-hydroxyvitamin D [25(OH)D], PTH, calcium, and alkaline phosphatase. RESULTS: The study included 35 patients with RTT and 35 age-matched females with other neurological diseases. The median serum 25(OH)D concentration in the RTT group was 26.25 nmol/L, with values <75 nmol/L in all participants. Severe deficiency (<25 nmol/L) was detected in 17 of 35 (48.6%) patients. The median 25(OH)D concentration was significantly lower in patients with RTT than in control subjects. The risk for fracture by 12 years of age in patients with RTT was 35.3%. An inverse correlation of the 25(OH)D level to age and PTH level was detected. Patients receiving antiepileptic polytherapy had a 3.3 times greater chance for severe vitamin D deficiency than patients receiving monotherapy. CONCLUSION: The prevalence of vitamin D deficiency in patients with RTT is higher than that in patients with other neurological diseases. The high risk for vitamin D deficiency should be accounted for in the strategy of antiepileptic treatment in RTT, especially when polytherapy is considered.

Newborn screening for cystic fibrosis in Serbia: a pilot study.

BACKGROUND: We performed a pilot study of neonatal screening for cystic fibrosis (CF) in order to introduce it to the national screening program in Serbia. METHODS: Immunoreactive trypsinogen (IRT) concentrations were analyzed in dried blood spot samples. Patients were recalled for repeated measurements in case of high IRT levels. Persisting high IRT levels resulted in DNA testing for the 29 most common mutations in the CF transmembrane regulator (CFTR) gene (IRT/IRT/DNA method). Sweat chloride measurements and clinical assessment were further performed for newly diagnosed patients. RESULTS: Of 1000 samples, three were initially positive and were further analyzed for the presence of the most common CFTR mutations in the Serbian population. DNA analysis revealed two patients being homozygous for F508del mutation. One sample was false positive, as the genetic test proved to be negative and associated with normal sweat chloride concentration and unremarkable clinical presentation. CONCLUSIONS: The results of our pilot study justified the expanding of the routine neonatal screening program in Serbia with CF. Data could be used in future in order to obtain accurate incidence of CF and carrier prevalence in our country.

[Very long chain fatty acids in the pathogenesis, prenatal and postnatal diagnosis of X-linked adrenoleukodystrophy].

INTRODUCTION: X-linked adrenoleukodystrophy (X-ALD) is a hereditary disorder of peroxisomal metabolism, biochemically characterized by accumulation of saturated very long chain fatty acids. DIAGNOSIS OF X-ADRENOLEUKODYSTROPHY: The biochemical diagnosis of X-linked adrenoleukodystrophy is done by gas-chromatographic analysis of plasma very long chain fatty acids. Accumulation of these fatty acids is associated with cerebral demyelination, peripheral nerve abnormalities, adrenocortical insufficiency and it may play a role in the pathogenesis of the brain inflammatory response. GENETIC COUNSELING AND PRENATAL DIAGNOSIS: Detection of familial index cases is important for diagnosis of further cases of X-ALD, treatment of asynmptomatic or barely symptomatic cases to avoid or delay symptom development of heterozygotes, and for providing genetic counseling and prenatal diagnosis in high risk persons. CONCLUSION: Retroviral mediated gene transfer corrects VLCFA metabolism in several months in cultured skin fibroblasts obtained from patients with X-ALD. Therefore, there is a hope that in the near future gene therapy may become available for those affected by this severe and potentially lethal disease.

X-linked adreno leukodistrophy: Profiles of very long chain fatty acids in plasma and fibroblasts in eigth Serbian patients.

X-linked adrenoleukodistrophy is a severe neurodegenerative disorder with impaired very long chain fatty acid metabolism. The disease associated ABCD1 gene encodes a peroxisomal membrane protein which belongs to the superfamily of ATP-binding cassette transporters. We investigated eight male X-ALD patients diagnosed among 142 suspected patients referred for investigation. Plasma levels of very long chain fatty acids were measured at our laboratory using capillary gas chromatography. Eight cases of childhood X-ALD were diagnosed. This is the first published series of Serbian patients with X-ALD. In addition, diagnosis identifies carriers, which could be benefit for genetic counselling and prenatal diagnosis.

Urinary catecholamine metabolites: Capillary gas chromatography method and experience with 12 cases of neuroblastoma.

We propose a rapid, simple metodology for routine analysis of human urine to detect vanillylmandelic and homovanillic acid related to neuroblastoma. The assay were specific capillary gas chromatography with flame ionization detection. In this methodology an internal standard is used and the procedure involves ethyl ester formation without isolation of the compounds of interest. The run time is 36 minutes. We also report quantitative results for urinary vanillylmandelic and homovanillic acid in neuroblastoma patients, demonstrating the diagnostic value of this method.