Genotype-phenotype correlation in 44 Czech, Slovak, Croatian and Serbian patients with mucopolysaccharidosis type II.

Mucopolysaccharidosis type II (Hunter syndrome, MPS II, OMIM 309900) is an X-linked lysosomal storage disorder caused by deficiency of iduronate-2-sulfatase (IDS). We analyzed clinical and laboratory data from 44 Slavic patients with this disease. In total, 21 Czech, 7 Slovak, 9 Croatian and 7 Serbian patients (43 M/1 F) were included in the study (median age 11.0 years, range 1.2-43 years). Birth prevalence ranged from 1:69,223 (Serbia) to 1:192,626 (Czech Rep.). In the majority of patients (71%), the disease manifested in infancy. Cognitive functions were normal in 10 patients. Four, six and 24 patients had mild, moderate, and severe developmental delay, respectively, typically subsequent to developmental regression (59%). Residual enzyme activity showed no predictive value, and estimation of glycosaminoglycans (GAGs) had only limited importance for prognosis. Mutation analysis performed in 36 families led to the identification of 12 novel mutations, eight of which were small deletions/insertions. Large deletions/rearrangements and all but one small deletion/insertion led to a severe phenotype. This genotype-phenotype correlation was also identified in six cases with recurrent missense mutations. Based on patient genotype, the severity of the disease may be predicted with high probability in approximately half of MPS II patients.

Phthalates deregulate cell proliferation, but not neuroendocrine transdifferentiation, in human LNCaP prostate cancer cell model.

Phthalate esters are ubiquitous environmental pollutants widely used as plasticizers, which have been shown to interfere with both endocrine regulation and development of reproductive organs. In the present study, we examined the impact of diethylhexyl phthalate (DEHP) and dibutyl phthalate (DBP) on the proliferation of androgen-sensitive human prostate carcinoma LNCaP cells and related events. The results showed that both compounds were able to inhibit cell cycle progression in a dose-dependent manner. However, only DEHP was found to weakly reduce androgen receptor (AR) protein levels after long-term exposure, while only DBP partially inhibited expression of the prostate-specific antigen (KLK3) gene, a model AR transcriptional target. This indicated that inhibition of cell proliferation was likely independent of any AR modulations. Both phthalates induced suppression of cell proliferation, but none of them affected the levels of markers associated with neuroendocrine transdifferentiation (NED) in LNCaP cells. Taken together, the presented data indicate that phthalates may exert long-term negative effects on the proliferation of prostate epithelial cells derived from the carcinoma model, which are, nevertheless, largely independent of the modulation of AR expression/activity, and which do not alter further processes associated with NED.

Acute hyperammonaemic encephalopathy in a female newborn caused by a novel, de novo mutation in the ornithine transcarbamylase gene.

UNLABELLED: A full-term female offspring of a first and uneventful pregnancy presented at 60 h of life with irritability, tachypnea and respiratory alkalosis progressing to deep coma with clinically dominant circulatory failure, tachycardia and hypotension. Diagnosis of ornithine transcarbamylase (OTC) deficiency was made on the basis of hyperammonaemia, hypocitrullinaemia and extreme hyperexcretion of orotic acid. The baby was treated with peritoneal dialysis, arginine hydrochloride and adequate energy supply. DNA analysis revealed an as of yet unidentified missense mutation in the 6th exon of the OTC gene, resulting in a change of lysine to glutamine at position 210 (K210Q). Her parents were not found to carry this mutation, implying that this mutation may have occurred either de novo in the patient or in a parental germ cell. CONCLUSION: An acute neonatal form of OTC deficiency should be considered in the differential diagnosis of coma in female newborns.

[Disorders of mitochondrial energy metabolism in patients with the Kearns-Sayre syndrome]. / Poruchy mitochondriálního energetického metabolizmu u pacientu s Kearns-Sayreovým syndromem.

BACKGROUND: Kearns-Sayre syndrome is a multisystem disorder caused by rearrangements of mitochondrial genome including various deletions and/or duplications. The aim of the study is to analyse the impact of mitochondrial DNA (mtDNA) deletions on the mitochondrial energetic metabolism in five patients with Kearns-Sayre syndrome. METHODS AND RESULTS: The course of the disease is progressive in all patients. All of them have bilateral ptosis and external opthalmoplegia, four have retinitis pigmentosa, three have progressive muscle weakness and three have pacemaker because of complete A-V heart block. One patient underwent renal transplantation at the age of 12 because of a chronic renal failure. Southern blot analysis in muscle tissue revealed large scale heteroplasmic mtDNA deletions (3-7.4 kb) in all patients, the number of mutated copies of mtDNA ranged from 50 to 70%. Spectrophotometric measurements of respiratory chain complexes activities in muscle tissue revealed various combinations of defects of complex III, IV and I + III activities in all patients. Nevertheless, the lactic acidosis was permanently present only in one patient. Ragged-red fibers were found in two patients. CONCLUSIONS: Although the diagnostic of Kearns-Sayre syndrome is based on clinical features, molecular analysis of mtDNA is necessary to confirm the diagnosis. The prognosis of the disease is unfavourable and co-operation between the patient and various specialists is necessary for the treatment, which is currently only symptomatic.

[Metabolic complications and neurologic manifestations of vitamin B12 deficiency in children of vegetarian mothers]. / Metabolické komplikace a neurologické projevy pri deficitu vitaminu B12 u detí vegetariánských matek.

BACKGROUND: Serious hematological, metabolic and neurological complications owing to the nutritional deficiency of vitamin B12 may occur in infants of mothers on a strict vegetarian diet. METHODS AND RESULTS: The mother of the first child was a strict vegetarian. She had an elevated urinary methylmalonic acid level and a low concentration of serum vitamin B12. Her 13-month-old daughter was exclusively breast-fed until the age of 9 month and then she was fed only vegetables. Physical examination revealed psychomotoric retardation, apathy, muscular hypotonia, abnormal movements and failure to thrive. Laboratory analysis showed a megaloblastic anaemia, a low level of vitamin B12 and methylmalonic aciduria. MRI of the brain revealed diffuse frontotemporoparietal atrophy and retardation of myelination. After treatment with vitamin B12 supplements, abnormal movements disappeared and development improved, but a mild generalised hypotonia continued. A cranial MRI 9 months after treatment still showed signs of retardation of myelination. The second patient, an 8 month-old male, son of a strict vegetarian mother too, was referred for investigation of psychomotoric retardation, hypotonia, dyskinesia, failure to thrive and microcephaly. He was breast-fed and from 6 month of age he had also received fruit juices. Laboratory analysis revealed megaloblastic anaemia, high methylmalonic aciduria and homocystinuria. The patient's and his mother's serum level of vitamin B12 were low. After treatment with vitamin B12 supplements, biochemical and metabolic markers of disease were normal but there continued a generalised hypotonia, microcephaly and language delay. CONCLUSION: Our observations emphasize the health complications of nutritional cobalamine deficiency and a requirement of clinical, biochemical and metabolic monitoring in infants within strict vegetarian families.

[Various manifestations of the A8344G mtDNA heteroplasmic mutation in 4 families with the MERRF syndrome]. / Rozmanitost projevu heteroplazmické mutace A8344G mtDNA ve ctyrech rodinách se syndromem MERRF.

BACKGROUND: The most frequent manifestation of mitochondrial DNA (mtDNA) mutation 8344 A-->G is MERRF syndrome (Myoclonic Epilepsy and Myopathy with Ragged Red Fibres). Less frequent symptoms include ataxia, perceptive type of deafness, cardiomyopathy or external ophthalmoplegia and mental and motor retardation in children. We describe heterogeneity of clinical symptoms and results of biochemical and molecular investigations in four families with the heteroplasmic mutation 8344 A-->G in mtDNA. METHODS AND RESULTS: In co-operation with paediatric, neurological and genetic specialists from the Czech and Slovak Republic we found in 1993-1998 at the enzymatic or molecular level more than 90 children and adults with impaired mitochondrial energy metabolism. Heteroplasmic mutation 8344 A-->G in mtDNA was found in four families. Ataxia and progressive muscle weakness appeared in the first proband with 50% of mutated copies of mtDNA in muscle at the age of 30 years. The second proband with 95% of mutated mtDNA had his first clinical symptoms--muscle hypotonia, cardiomyopathy and mental and motor retardation--in infancy while his four relatives with 25-50% mutated mtDNA lack so far clinical symptoms. In a female from the third family with 50% mutated mtDNA in muscle the disease manifested at the age of 42 years with progressive external ophthalmoplegia (PEO) and muscle weakness. In the fourth proband with 50% of mutated mtDNA in blood the disease started in infancy with spastic quadruparesis and arrested mental and motor development. Enzymatic and histochemical investigation in muscle biopsy in two probands revealed lower cytochrom c oxidase activity. Ragged-red fibres were found only in one adult patient. CONCLUSIONS: MtDNA mutation 8344 A-->G can manifest by heterogeneous symptoms. A higher percentage of mutated mtDNA is usually associated with more serious forms of the disease, but there is not always a correlation between the degree of heteroplasmy and severity of the disease or the age of the first clinical symptoms.

[Lactate acidosis in childhood]. / Laktátová acidóza v detském veku.

BACKGROUND: Secondary lactate acidosis is found in children with hypoxaemia, with impaired tissue perfusion, in hepatic and renal failure or in intoxications. Primary lactate acidosis is usually caused by hereditary metabolic disorders. The objective of the trial was to analyze the causes which lead in childhood to the development of primary hyperlactacidaemia. METHODS AND RESULTS: The authors examined during 1995-1996 the lactate and pyruvate concentration in 479 children referred by paediatric and neurological departments with a suspect hereditary metabolic disturbances. A raised lactate in blood or cerebrospinal fluid > 2.3 mmol/l was found in 230 children incl. 49 where a metabolic disorder was detected. Ten children had impaired cytochrome c oxidase, two children had a combined deficience of NADH dehydrogenase and cytochrome c oxidase, three children had a deficience of the pyruvate dehydrogenase (PDH) complex, one child had a deficience of ATP synthase and seven children suffered from impaired beta-oxidation. Glycogenosis type I, III or IX was found in 13 children. In three children organic aciduria was found, two children had an impaired urea cycle and three children impaired fructose metabolism. In five children a low level of free and total carnitene was found as a result of valproate treatment. A significant increase of the lactate level by more than 1 mmol/l during an oral glucose load was found in 11 of 16 children with impairment of the respiratory chain or PDH complex. In 58 children concurrently lactate in blood and cerebrospinal fluid assessed but no correlation of lactate levels was found. CONCLUSIONS: In patients with suspect hereditary metabolic disorders examination of lactate, pyruvate and alanine levels can be considered a screening test for detection of mitochondrial disorders. It remains difficult to reveal the cause of hyperlactacidaemia in a sick child even if a wide range of laboratory methods are used which contribute to the diagnosis of hereditary metabolic disorders.