Congenital disorders of glycosylation - an umbrella term for rapidly expanding group of rare genetic metabolic disorders - importance of physical investigation.

AIM: Congenital disorders of glycosylation (CDG) belong to an expanding group of rare genetic metabolic disorders caused by defects in the complex chemical enzymatic process of glycosylation. The study is aimed at presenting a case report of a premature dysmorphic newborn, clinical presentation of the condition, the way it was diagnosed and treated, as well as its comparison with the known cases. RESULTS: The result of glycan analysis supports the assumption of a supposed glycosylation disorder and also specifies a specific subtype: CDG-1, subtype ALG12-CDG (Ig). CONCLUSION: CDG have an extremely wide clinical spectrum and should be considered in any child with unexplained developmental delay, failure to thrive, seizures, and abnormalities in liver enzymes, coagulation and immunologic factors. The treatment of most forms of CDG depends upon numerous factors such as specific symptoms present, severity of the disorder, age and overall health of the patients and tolerance to certain medications or procedures. For these reasons, the treatment is specific for every individual. It is based on the symptoms and requires a coordination of efforts of a team of specialists (Tab. 4, Fig. 3, Ref. 19).

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.

GAI - distinct genotype and phenotype characteristics in reported Slovak patients.

OBJECTIVES: The clinical, biochemical and genetic findings in two Slovak patients with glutaric aciduria type I (GAI) are presented. BACKGROUND: GAI is a rare autosomal recessive neuro-metabolic disorder caused by deficiency of glutaryl-CoA dehydrogenase, which is involved in the catabolic pathways of lysine, hydroxylysine and tryptophan. This enzymatic defect gives rise to elevated levels of glutaric acid (GA), 3-hydroxyglutaric acid (3-OH-GA) and glutarylcarnitine (C5DC) in body fluids. METHODS: Biochemical and molecular-genetic tests were performed. Urinary organic acids were analysed by Gas Chromatography/Mass Spectrometry (GC/MS) and the entire coding region of the GCDH gene, including flanking parts, was sequenced. RESULTS: We found the presence of typical metabolic profile and novel causal pathogenic variants in both GAI patients. CONCLUSION: We present the first report of two Slovak patients with GAI, which differed in the clinical and biochemical phenotype significantly. They were diagnosed by two distinct approaches - selective and newborn screening. Their diagnosis was complexly confirmed by biochemical and later on molecular-genetic examinations. Though we agreed with a thesis that early diagnostics might positively influenced patient's health outcome, contradictory facts should be considered. Supposed extremely low prevalence of GAI patients in the general population and/or the existence of asymptomatic individuals with a questionable benefit of the applied therapeutic intervention for them lead to doubts whether the inclusion of disease into the newborn screening programme is justified well enough (Tab. 1, Fig. 3, Ref. 41).

Ophthalmological finding in a patient with lowe syndrome.

The authors present the ophthamological finding in a patient who at the age of 4.5 months was admitted due to a finding of total bilateral congenital cataract. The patient was observed by a neurologist for central hypotonia and mental retardation. Upon a complex examination of the patient, suspicion of Lowe syndrome was stated, which was confirmed by a metabolic examination and also by genetic tests. Upon an examination of the family, a genetic defect (mutation of OCRL1 gene) was confirmed also in the mother of the patient. A mild subcapsular opacification was present in the mother, beneath the posterior capsule. The patient was operated on for bilateral congenital cataract. Upon an examination under general anaesthesia, trabeculodysgenesis was diagnosed. Intraocular pressure remains within the norm. The patient is now aged 8 years, regularly monitored with regard to metabolic compensation, and by a neurologist and ophthalmologist, with satisfactory visual functions. Early diagnosis of the Lowe syndrome was determined on the basis of a complex examination of the patient within the framework of etiological diagnosis of bilateral congenital cataract. Key words: Lowe syndrome, oculo - cerebro - renal syndrome, congenital cataract, glaucoma, nystagmus.

Mutation analysis of the GALT gene in Czech and Slovak galactosemia populations: identification of six novel mutations, including a stop codon mutation (X380R).

A study of the galactose-1-phosphate uridyltransferase (GALT) gene from 37 unrelated galactosemia families is reported here. A total of 16 sequence variations in eleven mutated alleles was found. The two most common molecular defects were the mutations Q188R (46.0%) and K285N (25.7%). Six novel mutations in the GALT gene, X380R, Y209S, E340K, L74fsdelCT, Q169K and L256/P257delGCC, were detected. Three mutations, V151A, L195P and R204X that were previously described in other populations, were also found. The mutation X380R, which breaks the stop codon of the GALT gene, causes elongation of the GALT enzyme's protein chain. A deletion of four nucleotides in the 5' promoter region, in a position 116 - 119 nucleotides upstream from the initiate codon (5'UTR-119delGTCA), was revealed in Duarte (D2) alleles, in addition to N314D, IVS4nt-27g-->c, IVS5nt+62g-->a, and IVS5nt-24g-->a. An unusual molecular genotype was observed on 2 types of classical galactosemia alleles, with six variations from the normal nucleotide sequence presented in cis (mutation V151A or E340K plus five Duarte (D2) characteristic variations). In summary, galactosemia is a heterogeneous disorder at the molecular level, and mutation N314D, appears to be an ancient genetic variant of the GALT gene. Hum Mutat 15:206, 2000.

[Familial supravalvular aortic stenosis]. / Familiárna supravalvulárna aortálna stenóza.

By means of two dimensional echocardiography supravalvular aortic stenosis was diagnosed in two siblings and their cousin. Autosomal dominant transmission with incomplete penetrance or even non-penetrance is assumed to be involved. Somatic stigmatization, typical for Williams' syndrome, failed to be present in the affected children. The reported family provides further evidence that familial supravalvular aortic stenosis and Williams' syndrome are two distinct clinical entities. (Tab. 1, Fig. 3, Ref. 23.)

[Surgical treatment of supravalvular aortic stenosis]. / Operacná liecba supravalvulárnej aortálnej stenózy.

Over the last 22 years, two children were operated on for supraventricular aortic stenosis at the Institute of Cardiovascular Diseases in Bratislava. Both cases presented a localized form of supravalvular aortic stenosis. Simple elipsoid flaps were used without extended aortoplasty. One of the two children, a 12-year-old boy with Williams' syndrome died of endocarditis in the early postoperative period. In the 10-year-old girl with familial supravalvular aortic stenosis the operation was successful, although the defect was combined with supravalvular muscular obstruction. The authors emphasize the possibility of choice between two surgical procedures according to the localization of the stenosis with respect to the valvular apparatus.

Trisomy 18 mimicking Smith-Lemli-Opitz syndrome in the immediate neonatal period.

The study describes a dysmorphic newborn infant with life-threating anomaly, later diagnosed as trisomy 18, mimicking Smith-Lemli-Opitz syndrome in the immediate neonatal period. The establishment of the correct diagnosis in the first days of life is very important for the decision-making process, because trisomy 18 has a poor prognosis, and treatment is not instituted, whereas cholesterol supplementation may be of benefit to patients with Smith-Lemli-Opitz syndrome. Ultraviolet spectrophotometry showed very easy and rapid method for differentiation of both syndromes, where gas chromatography/mass spectrometry analysis is not available. (Fig. 2, Ref: 18.)

[Diagnosis of supravalvular aortic stenosis using 2-dimensional echocardiography]. / Diagnostika supravalvulárnej aortálnej stenózy pomocou dvojrozmernej echokardiografie.

In 13 children supravalvular aortic stenosis was diagnosed by two-dimensional echocardiography on the basis of a diminished inner diameter of the aorta in the supravalvular region "d2" compared with the inner diameter of the aortic annulus "d1". The differences in the values of "d2" and "d1" were only on the border of statistical significance. The difference in the d2/d1 ratio between the group of patients and healthy controls was statistically significant (p less than 0.001). Two-dimensional echocardiography is a very sensitive method for diagnosing supravalvular aortic stenosis. This sensitivity has been confirmed also by detecting the diminished inner diameter of the aorta in the supravalvular region in children with Williams-Beuren syndrome without clinical signs of a heart defect.

A case of Rett syndrome from Ukraine--clinical diagnosis confirmed by mutation analysis of the MECP2 gene.

Rett syndrome (RTT) is an X-linked disorder caused by mutations in the methyl-CpG-binding protein 2 gene (MECP2). The incidence is 1:10,000-1:15,000 females worldwide. To date, the mutational spectrum of MECP2 in the Ukrainian population is not known. Here we present first Ukrainian girl with classic clinical signs of RTT, in whom mutation of MECP2 gene was detected. Total genomic DNA was extracted from a dry blood spot using the QIAamp DNA Mini Kit (Qiagen) according to the manufacturer's protocol. Genomic DNA was used to amplify coding sequence and exon/intron borders of MECP2 gene. Products were examined by restriction analysis and automatic direct sequencing. The sequencing analysis of our patient revealed a small deletion of 4 bases AAAG at position 856-859 in exon 4 of MECP2 gene (856-859del4). This mutation leads to a frameshift (K286fs) and a premature stop codon. The creation of premature stop codon results in synthesis of truncated MeCP2 protein. Localization of the mutation into the transcription repression domain (TRD) probably affects the function of MECP2 protein in the process of transcriptional repression. To our knowledge this is the first case from Ukraine, in whom clinical diagnosis of RTT was confirmed by mutation analysis of MECP2 gene. Mutation analyses of further patients are needed to establish the spectrum of MECP2 mutations in the Ukrainian population. (Tab. 1, Fig. 3, Ref. 22.)

Metabolic cause of Reye-like syndrome.

The most frequent metabolic cause of Reye-like syndrome is medium chain acyl-CoA dehydrogenase (MCAD) deficiency. The authors describe a gypsy boy who was repeatedly hospitalised due to symptoms of Reye-like syndrome (serious hypoglycemia, loss of consciousness, seizures, increased values of aminotransferases, decreased values of free carnitine). The diagnosis of MCAD deficiency was established by analysis of plasmatic acylcarnitines by use of tandem mass spectrometry. DNA analysis proved the most common K329E (G985) mutation in gene for MCAD deficiency in homozygous state. The authors have emphasised the advantage of tandem mass spectrometry in the diagnosis of disorders of fatty acid beta-oxidation. This highly sophisticated method can detect most of these disorders from dry blood spots disregarding the symptoms and type of mutation.

[Chromosome aberrations in children with the Williams-Beuren syndrome]. / Chromozómové aberácie u detí s Williamsovým-Beurenovým syndrómom.

Karyotypic examinations were carried out in 10 children suffering from Williams-Beuren's syndrome. Chromosomal aberrations were established in two of the children. In one case the mosaic pattern of Klinefelter's syndrome was recorded, evidently presenting an instance of coincidence. In the other case deletion of the long arm of chromosome 6 (q22.2q23) was demonstrated, which according to the authors' hypothesis may represent an alternative localization of the phenotypic traits of Williams-Beuren's syndrome or of its assumed underlying defect, namely derangement of the regulation of calcium metabolism. The value of cytogenetic examination of children with Williams-Beuren's syndrome in elucidating the so far obscure pathogenesis of this disease is being emphasized.

Serum free carnitine in medium chain acyl-CoA dehydrogenase deficiency.

Medium chain acyl-CoA dehydrogenase (MCAD) deficiency is the most common disorder of fatty acid beta-oxidation and presents acutely with hypoglycemia, or a Reye-like illness with low free carnitine, often provoked by an infection or an excessive period of fasting. After acute attack these children are for the most time asymptomatic and may have normal plasma free carnitine concentrations. We observed a regularity in time course of serum free carnitine concentration during two attacks of Reye-like illness in patient with MCAD deficiency. Molecular investigation confirmed that the patient was homozygote for A985G mutation. Free carnitine was measured by enzymatic UV-test. First attack of severe hypoglycemia and Reye-like symptoms started at the age of 15 months and the second at the age of 25 months. In both episodes, treatment with intravenous glucose was given immediately, but without carnitine supplementation. Between the attacks patient was on a normal diet. In both attacks, low serum free carnitine concentration from the time of acute attack continually decreased for up to 8-13 days and then normalized at about 25 days after attack. We think that the time course of serum free carnitine may help in knowledge about carnitine depletion in MCAD deficiency. This is the first observation of this pattern during an acute attack and needs to be confirmed by other patients with MCAD deficiency. (Fig. 2, Ref. 7.).

[Increased acid phosphatase in isolated transitory hyperphosphatasemia]. / Zvýsenie kyslej fosfatázy pri izolovanej tranzitórnej hyperfosfatazémii.

In a 13-month-old girl with typical signs of isolated transient hyperphosphatasaemia the authors found repeatedly elevated acid phosphatase values. This finding supports the hypothesis of a temporary increase of bone remodelling in this condition.

[History of Williams syndrome]. / História Williamsovho syndrómu.

History of the Williams syndrome (WS) represents a process of detailed analysis of phenotypic markers and of attempts to reveal their origin. This demanding tasks have brought many valuable findings, which were employed in different fields of medicine, namely in cardiology, metabolism, genetics, psychology and cognitive neurosciences. Discovery of the genetic basis of the disease closed the first period of the syndrome analysis. Genetic studies have been proceeding and WS can be taken as a model syndrome for the behavioral genes identification. Similarly the description of the pathogenesis of vascular anomalles represents the key for understanding of the pathogenesis of other, more common vascular diseases. The article brings the review of the history of the WS.

[A new approach to cholesterol]. / Nový pohlad na cholesterol.

Although much is known about hypercholesterolemia and the associated risk for the development of atherosclerosis, very little research has focused on altered cholesterol biosynthesis. Recent discovery that the biochemical basis for the human malformation syndrome, Smith-Lemli-Opitz syndrome appears to lie in altered cholesterol biosynthesis has changed this situation. Cholesterol has an extraordinary important functions in organism. Recommendations to lower serum cholesterol are widespread, yet low serum cholesterol is associated with poorly understood morbidity. Cholesterol is still an enigmatic, essential metabolite and much remains to learn about it.

[How can the Williams-Beuren syndrome be recognized?]. / Ako poznáme Williamsov-Beurenov syndróm?

In a girl with Williams-Beuren's syndrome psychological examination revealed mental retardation with a special mental profile, angiography revealed peripheral pulmonary stenoses, echocardiography a slight stenosis in the supravalvular aortal area and anthropometry typical facial signs. Indirect signs of hypercalcaemia were clinical signs of poor progress during infancy. The authors emphasize that accurate analysis of basic clinical signs and the natural development of the disease are the key to its diagnosis.

[Clinical picture of homocystinuria with cystathionine beta-synthase deficiency in 19 Czech and Slovak patients]. / Klinický obraz homocystinurie z deficitu cystathionin beta-syntázy u devatenácti ceských a slovenských pacientu.

BACKGROUND: Homocystinuria due to cystathionine beta-synthase deficiency is an autosomal recessive disorder of methionine metabolism. It manifests with vascular, central nervous system and connective tissue disturbances, and phenotypically resembles Marfan's syndrome. We analysed the clinical course of homocystinuria in Czech and Slovak patients. METHODS AND RESULTS: The group of homocystinuric patients consisted of 19 individuals (12 males and 7 females) aged 5-32 years (average age 18 years), who were diagnosed between 1980 and 1999. The overall incidence of homocystinuria in the Czech and Slovak Republics was 1:287,000. The proportion of pyridoxine-responsive patients was 47%. The average follow-up period was 10 years (range 1 month to 19 years). The prevalence of the individual signs in the group was as follows: lens dislocation--95% of patients, progressive myopia--79%, marfanoid habitus--74%, kyfoscoliosis--68%, osteoporosis--63%, psychomotor retardation--58%, other neurologic symptomatology--58% and tromboembolism--21%. The average delay between the first sign of the disease and the time when the diagnosis was made was 4 years (range 1 to 14 years). At the time of diagnosis the average levels of metabolites in plasma were as follows: total homocysteine 348 mumol/l (range 211-536), free homocystine 70 mumol/l (range 0-203) and methionine 359 mumol/l (range 75-937). CONCLUSIONS: Both the clinical course of homocystinuria due to the cystathionine beta-synthase deficiency and its incidence in the Czech and Slovak Republics are similar to those in other populations. Since homocystinuria is a treatable disease, it should be included in the differential diagnosis of Marfan's syndrome, tromboembolism and severe psychomotor retardation.

[Molecular analysis of Wilson disease]. / Molekulární analýza Wilsonovy choroby.

BACKGROUND: Wilson disease is an autosomal recessive disorder, characterized by cooper accumulation and intoxication of the organism. Molecular basis of the disease represent mutations in the gene for the copper-transporting ATPase (ATP7B). METHODS AND RESULTS: The submitted paper deals with results of molecular-genetic examination in 130 unrelated families in which Wilson disease was diagnosed. By denaturing gradient gel electrophoresis (DGGE), the exons with abnormal sequences were detected. Followed by sequencing, 17 causal mutations and 9 silent polymorphism were found. Five novel mutations were detected. After analysis of 260 mutant alleles, 214 (82.3%) were identified. The most frequent mutation, H1069Q, occurred in our population with the frequency of 65.8%. Incidence of other mutations, however, did not exceed 5%. CONCLUSIONS: DNA analysis of the Wilson disease offers prompt and reliable results in affected families. It can help to identify asymptomatic and heterozygote siblings at genetic counselling.

[Transitory hyperphosphatasemia in childhood]. / Tranzitórna hyperfosfatazémia detského veku.

Transient hyperphosphatasaemia was detected in 11 children hospitalized at the First and Second Paediatric Clinic of the Paediatric Faculty Hospital in Bratislava in 1985-1990. The authors analyzed retrospectively 6 children from this group where it was possible to evaluate accurately the trend of serum alkaline phosphatase. In all children the high alkaline phosphatase activity was detected incidentally during the initial examination. The reason for hospitalization were in four instances respiratory infections, in one instance coeliac disease and in one instance infectious mononucleosis with infection of the urinary pathways. The maximum increase of serum alkaline phosphatase was 5-15 fold higher than the upper borderline of the reference range for the given age group. The activity declined to normal spontaneously independently on the course of the basic disease and treatment, always in the course of 3-12 weeks. The isoenzyme pattern of alkaline phosphatase with a high ratio of the thermolabile isoenzyme was typical. Finally the authors emphasize that recognition of this obscure condition which does not endanger life can spare the children many unnecessary and expensive examinations.