Microheterogeneity of some serum glycoproteins in neurodegenerative diseases.

Background: Participation of protein polymorphism is often considered in the pathogenesis of various diseases. Aberrant protein glycosylation has been recognized to play major roles in human disorders, including neurodegenerative diseases.

Objective: The aim of the study was to examine possible involvement of protein genetic variants and degree of glycosylation of some serum glycoproteins in the manifestation of neurodegenerative disorders in a Czech population sample.

Clinical and diagnostic approach in unsolved CDG patients with a type 2 transferrin pattern.

Dysmorphic features, multisystem disease, and central nervous system involvement are common symptoms in congenital disorders of glycosylation, including several recently discovered Golgi-related glycosylation defects. In search for discriminative features, we assessed eleven children suspected with a Golgi-related inborn error of glycosylation. We evaluated all genetically unsolved patients, diagnosed with a type 2 transferrin isofocusing pattern in the period of 1999-2009.

Amniotic fluid α-fetoprotein microheterogeneity in the prenatal diagnosis of congenital disorders of glycosylation type Ia.

Background: Congenital disorders of glycosylation are a group of clinically and biochemically diverse defects. The current screening method (based on analysis of transferrin), which is used postnatally for the most frequent types, is however not suitable for prenatal diagnosis. The aim of the study was to investigate whether alterations in the microheterogeneity of α-fetoprotein would provide more reliable results.

Transferrin D protein variants in the diagnosis of congenital disorders of glycosylation (CDG).

Congenital disorders of glycosylation are a rapidly growing group of inherited (neuro)metabolic disorders characterized by defects in glycosylation of proteins and lipids. This study discusses an analytical problem in the differentiation between hypoglycosylation and transferrin (Tf) protein variants. Analysis of serum Tf by isoelectric focusing is used as a common method suitable for screening 19 out of a total of 22 types of glycosylation defects identified so far.

Genetic variants of transferrin in cystic fibrosis.

Background: Genetic polymorphism of serum transferrin (Tf) was studied in order to differentiate between protein genetic variants and congenital disorders of glycosylation (CDG), further focusing on unusual findings.

Methods: Screening of Tf hypoglycosylation was carried out by isoelectric focusing with direct immunofixation and Coomassie blue staining in 100 healthy controls and a group of 1247 patients with various symptoms and diagnoses.

Results: Of the seven different genotypes detected, a significantly higher (p = 0.

Screening and diagnosis of congenital disorders of glycosylation.

The aim of this paper is to review the diagnostics of congenital disorders of glycosylation (CDG), an ever expanding group of diseases. Development delay, neurological, and other clinical abnormalities as well as various non-specific laboratory changes can lead to the first suspicion of the disease. Still common screening test for most CDG types, including CDG Ia, is isoelectric focusing/polyacrylamide gel electrophoresis (IEF).

Inflammation and genes.

Inflammation is a protective immune response to infection, trauma, or injury; however, only a subset of patients develops inflammation, suggesting other contributing factors involved, such as the environment and genes. Inflammation-associated genes involving those with pro- and anti-inflammatory effect should be properly balanced and regulated; the protein products of these genes ultimately determine the outcome of inflammation. Apart from gene mutations, gene polymorphisms related to some inflammatory markers also appear to correlate with the incidence and/or outcome of serious inflammatory events.

Genetic variants of transferrin in the diagnosis of protein hypoglycosylation.

Human transferrin (Tf) shows genetic polymorphisms, which may interfere in the screening of congenital disorders of glycosylation (CDG). Isoelectric focusing followed by direct immunofixation was used for Tf analysis in controls and several groups of patients. Equivocal results in one case have been recognized as a rare Tf CD variant.

Pitfalls and drawbacks in screening of congenital disorders of glycosylation.

Congenital disorders of glycosylation include a group of diseases, each of them caused by different protein (mostly enzyme) impairment due to a specific gene defect. The many subtypes are classified according to clinical features, enzymology and molecular genetic analyses. Problems in diagnostics arise from the great diversity in clinical presentation, usually age-related, and different severities of individual types of these, by far underdiagnosed, diseases.

HPLC profiling of Trp-related metabolites in humans.

Screening for metabolic abnormalities of Trp has been introduced using SPE pre-treatment, TLC and/or two HPLC procedures. The excretory pattern in urine (occasionally also plasma and CSF levels) has been followed in a group of 390 children showing various symptoms of a metabolic defect and in 195 patients with skin diseases, namely those associated with photosensitivity, such as porphyria, vitiligo, alopecia, psoriasis, erythematodes, and others. Excretory abnormalities of either indican, kynurenine, 3-hydroxyanthranilic acid or indolylacryloylglycine have been occasionally combined with myopathy, seizures, liver and intestinal symptoms.

Microelements and inherited metabolic diseases.

In addition to the main groups of inherited metabolic diseases, including mitochondrial, peroxisomal and lysosomal defects, organic acidurias, porphyrias, defects of amino acids, saccharides and fatty acids metabolism, disorders of transport and utilisation of microelements have also been recognized. Recent findings concerning hereditary hemochromatosis (iron), Wilson and Menkes diseases (copper), molybdenum cofactor deficiency (molybdenum), defects of cobalamine synthesis (cobalt) and acrodermatitis enteropathica (zinc) are reviewed.

Genetic aspects of diabetes mellitus.

Practically all types of diabetes mellitus (DM) result from complex interactions of genetic and environmental factors. Multifactorial and polygenic Type 1 DM is strongly influenced by genes controlling the immune system, mainly HLA-DQ and DR. In addition to this, many other predisposition loci, interacting with each other, have some influence on susceptibility to DM.

[Clinical picture of homocystinuria with cystathionine beta-synthase deficiency in 19 Czech and Slovak patients].

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.

Metabolism of tryptophan in the liver: interference with decarboxylation of other aromatic amino acids.

Decarboxylation of aromatic amino acid in mammalian tissues is catalyzed by aromatic amino acid decarboxylase (EC. 4.1.

Screening for defects in tryptophan metabolism.

We introduced a two-step procedure for the detection of defects in metabolism of tryptophan: (1) HPTLC (described previously) is suitable when starting the investigation, (2) two HPLC methods with isocratic elution and spectrophotometric detection are used at the next step, when pathological findings are to be confirmed and the individual metabolites quantified. The first method enables the assessment of tryptophan, 5-hydroxyindolylacetic acid, indolylacetic acid, indolylacryloylglycine, indolylacrylic acid and its possible precursors, namely indolyllactic and indolylpropionic acids. The second procedure is intended for the monitoring of anthranilic, 3-hydroxyanthranilic, kynurenic and xanthurenic acids, kynurenine, 3-hydroxykynurenine and indoxyl-sulfate.

Where does indolylacrylic acid come from?

In addition to the main catabolic routes of tryptophan (Trp), there exist minor and less thoroughly investigated pathways; one of these leads to indolylacrylic acid (IAcrA). IAcrA is a plant growth hormone, whereas its biological role in animals is still obscure, as is the way and site where it is formed in the organism. A two-stage production is likely: Intestinal microorganisms catabolize Trp to indole derivatives which are then absorbed and converted to IAcrA and its glycine conjugate, indolylacryloylglycine (IAcrGly).

Screening for organic acid disorders.

The detection of organic acidurias is a part of our screening programme for inherited metabolic diseases. Adapted procedure is differentiated and involves several steps: 1) thin-layer chromatography (TLC) in the case of an abnormal finding followed by 2) gas chromatography (GC). The next step of the investigation, using 3) gas chromatography mass-spectrometry (GS-MS) is reserved for more complicated and dubious analyses.

High-performance liquid chromatographic profiling of indolylacryloylglycine and its possible precursors in body fluids.

Indolylacryloylglycine (IAcrGly) is one of the physiological components of urine, although its source and its role in the human organism have not yet been unambiguously established. Changes in the IAcrGly excretion level have been found under some physiological (age dependence, seasonal variations) and pathological (photodermatoses, muscle dystrophy, liver cirrhosis) conditions. The proposed method for IAcrGly, indolylacrylic acid and its possible precursors, namely indolyllactic and indolylpropionic acids, involves deproteinization and extraction of urine on a Sep Pak C18 cartridge.

Screening for biotinidase deficiency in some skin diseases.

Biotinidase deficiency is an inherited, autosomal recessive disorder involving gluconeogenesis, synthesis of fatty acids and catabolism of branched chain amino acids. As the cutaneous manifestations have been described to be a prominent part of the clinical picture, we tested a group of children and adults with various skin lesions. The blood-spot screening test was repeatedly (new disc and new card) positive in some patients suffering from psoriasis and atopic eczema.

Urinary excretion of indolylacryloylglycine, indolylacetic acid and 5-hydroxyindolylacetic acid in burn patients.

Indolylacryloylglycine (IAcrGly) is a regular constituent of human urine. Changes in its excretion have been observed, among other conditions, in some skin diseases. Skin lesions in burns are dealt with in the present paper.

Urinary excretion of some metabolites of tryptophan in malignant diseases.

The urinary excretion of four tryptophan metabolites, namely indolylacryloylglycine, indolylacetic, 5-hydroxyindolylacetic and 3-hydroxyanthranilic acids, was studied in two control groups, in children suffering from acute leukemia, hepatic and brain tumours and in adults with bladder cancer. Compared with controls, a significantly lower excretion of IAcrGly was observed in all patient groups with the exception of that with hepatic tumours. Hematological malignancies were further accompanied by low excretion of indolylacetic acid, and bladder cancers by a lower 5-hydroxyindolylacetic acid level.