Patient centered guidelines for the laboratory diagnosis of Gaucher disease type 1.

Gaucher disease (GD) is an autosomal recessive lysosomal storage disorder due to the deficient activity of the acid beta-glucosidase (GCase) enzyme, resulting in the progressive lysosomal accumulation of glucosylceramide (GlcCer) and its deacylated derivate, glucosylsphingosine (GlcSph). GCase is encoded by the GBA1 gene, located on chromosome 1q21 16 kb upstream from a highly homologous pseudogene. To date, more than 400 GBA1 pathogenic variants have been reported, many of them derived from recombination events between the gene and the pseudogene. In the last years, the increased access to new technologies has led to an exponential growth in the number of diagnostic laboratories offering GD testing. However, both biochemical and genetic diagnosis of GD are challenging and to date no specific evidence-based guidelines for the laboratory diagnosis of GD have been published. The objective of the guidelines presented here is to provide evidence-based recommendations for the technical implementation and interpretation of biochemical and genetic testing for the diagnosis of GD to ensure a timely and accurate diagnosis for patients with GD worldwide. The guidelines have been developed by members of the Diagnostic Working group of the International Working Group of Gaucher Disease (IWGGD), a non-profit network established to promote clinical and basic research into GD for the ultimate purpose of improving the lives of patients with this disease. One of the goals of the IWGGD is to support equitable access to diagnosis of GD and to standardize procedures to ensure an accurate diagnosis. Therefore, a guideline development group consisting of biochemists and geneticists working in the field of GD diagnosis was established and a list of topics to be discussed was selected. In these guidelines, twenty recommendations are provided based on information gathered through a systematic review of the literature and two different diagnostic algorithms are presented, considering the geographical differences in the access to diagnostic services. Besides, several gaps in the current diagnostic workflow were identified and actions to fulfill them were taken within the IWGGD. We believe that the implementation of recommendations provided in these guidelines will promote an equitable, timely and accurate diagnosis for patients with GD worldwide.

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.

Psycho-organic symptoms as early manifestation of adult onset POMT1-related limb girdle muscular dystrophy.

We report two siblings of Croatian consanguineous healthy parents with a novel homozygous missense mutation in the POMT1 gene, presenting with intellectual disability and psychotic, in particular hallucinatory symptoms and abnormal brain MRIs, preceding classical symptoms of limb-girdle muscular dystrophy by several years. Weakness became apparent in early adulthood and both siblings remained ambulant into the 3rd and 4th decade of life. The muscle biopsy showed reduced α-dystroglycan compatible with the POMT1 defect. This case report extends the phenotypic spectrum of POMT1 associated muscular dystrophies to the adult onset limb girdle muscular dystrophies with psycho-organic deficits.

Farber lipogranulomatosis type 1--late presentation and early death in a Croatian boy with a novel homozygous ASAH1 mutation.

BACKGROUND: We report a boy with an unusually late presentation of Farber lipogranulomatosis type l. CASE STUDY: The first symptoms appeared at the end of the first year of life in the form of joint swelling; other symptoms such as cherry-red spot, hoarseness, subcutaneous nodules appeared much later. The history of the disease, from the first symptoms till his early death, lasted 26.5 months. The neuronal dysfunction accompanied by the rapid neurological deterioration with seizures and myoclonias, rather than the general dystrophy, seemed to limit the duration of disease in our patient and provoked his early death. Diagnosis was confirmed by analysis of ceramide metabolism in cultured fibroblasts and of the ASAH1 gene, which indicated homozygosity for a novel point mutation. CONCLUSION: The deficient activity of acid ceramidase correlated well with poor prognosis of the disease in our boy, in contrast to late appearance of dermal nodules and the subsequent severe clinical course with fatal outcome. Farber lipogranulomatosis should be suspected in children with joint swelling as the first and only symptom of disease. In order to advance our knowledge towards establishing genotype-phenotype correlations in Farber's disease, detailed analysis of the ASAH1 gene is needed.

POMT1-associated walker-warburg syndrome: a disorder of dendritic development of neocortical neurons.

We have analyzed the morphology and dendritic development of neocortical neurons in a 2.5-month-old infant with Walker-Warburg syndrome homozygotic for a novel POMT1 gene mutation, by Golgi methods. We found that pyramidal neurons frequently displayed abnormal (oblique, horizontal, or inverted) orientation. A novel finding of this study is that members of the same population of pyramidal neurons display different stages of development of their dendritic arborizations: some neurons had poorly developed dendrites and thus resembled pyramidal neurons of the late fetal cortex; for some neurons, the level of differentiation corresponded to that in the newborn cortex; finally, some neurons had quite elaborate dendritic trees as expected for the cortex of 2.5-month-old infant. In addition, apical dendrites of many pyramidal neurons were conspiciously bent to one side, irrespective to the general orientation of the pyramidal neuron. These findings suggest that Walker-Warburg lissencephaly is characterized by two hitherto unnoticed pathogenetic changes in the cerebral cortex: (a) heterochronic decoupling of dendritic maturation within the same neuronal population (with some members significantly lagging behind the normal maturational schedule) and (b) anisotropically distorted shaping of dendritic trees, probably caused by patchy displacement of molecular guidance cues for dendrites in the malformed cortex.

Methods for a prompt and reliable laboratory diagnosis of Pompe disease: report from an international consensus meeting.

Pompe disease is an autosomal recessive disorder of glycogen metabolism caused by a deficiency of the lysosomal enzyme acid alpha-glucosidase (GAA). It presents at any age, with variable rates of progression ranging from a rapidly progressive course, often fatal by one-year of age, to a more slowly, but nevertheless relentlessly progressive course, resulting in significant morbidity and premature mortality. In infants, early initiation of enzyme replacement therapy is needed to gain the maximum therapeutic benefit, underscoring the need for early diagnosis. Several new methods for measuring GAA activity have been developed. The Pompe Disease Diagnostic Working Group met to review data generated using the new methods, and to establish a consensus regarding the application of the methods for the laboratory diagnosis of Pompe disease. Skin fibroblasts and muscle biopsy have traditionally been the samples of choice for measuring GAA activity. However, new methods using blood samples are rapidly becoming adopted because of their speed and convenience. Measuring GAA activity in blood samples should be performed under acidic conditions (pH 3.8-4.0), using up to 2 mM of the synthetic substrate 4-methylumbelliferyl-alpha-D-glucoside or glycogen (50 mg/mL), in the presence of acarbose (3-9 microM) to inhibit the isoenzyme maltase-glucoamylase. The activity of a reference enzyme should also be measured to confirm the quality of the sample. A second test should be done to support the diagnosis of Pompe disease until a program for external quality assurance and proficiency testing of the enzymatic diagnosis in blood is established.

Fumaric aciduria: mild phenotype in a 8-year-old girl with novel mutations.

Fumaric aciduria is a rare, autosomal recessive disorder caused by deficient activity of fumarate hydratase (FH). Common clinical features are hypotonia, failure to thrive, severe psychomotor retardation and seizures. Facial dysmorphism and brain malformations are frequent. Recently, some FH gene mutations have been associated with inherited cutaneous and uterine leiomyomas and papillary renal cell cancer. Our patient had a relatively mild phenotype, a previously not reported genotype and familial tumour predisposition. The mother and grandmother had uterine myomas. The paternal grandfather and his two brothers died from lung and laryngeal cancers. The pregnancy was complicated by bleeding and intrauterine growth retardation. Delivery was after 35 weeks, with normal Apgar score. The girl was hypotonic since birth. At age 2 months the parents noticed short apnoeic crises. She could sit at age 1.5 years, and walk with assistance at 4 years. At age 8 years highly increased excretion of fumaric acid was found twice (217 and 445 mmol/mol creatinine). Shortly before that the girl started to have leg and arm spasms. Grand mal seizures occurred twice. Facial dysmorphism included depressed nasal bridge, anteverted ears, hypertelorism and microcephaly. Speech was limited to few disyllables. She was atactic with spastic paraparesis. Brain MRI showed slight ventriculomegaly, white-matter atrophy and hypoplasia of corpus callosum. Activity of FH in fibroblasts was 1.9 nmol/min/mg protein (controls 40-80). Analysis of the FH gene revealed the maternally derived c.1029_1031delAGT mutation, resulting in Val deletion and substitution of Gln by His, and paternally derived c.976C > T mutation, resulting in substitution of Pro by Ser.

S-Adenosylhomocysteine hydrolase deficiency: a second patient, the younger brother of the index patient, and outcomes during therapy.

S-Adenosylhomocysteine (AdoHcy) hydrolase deficiency has been proven in a human only once, in a recently described Croatian boy. Here we report the clinical course and biochemical abnormalities of the younger brother of this proband. This younger brother has the same two mutations in the gene encoding AdoHcy hydrolase, and has been monitored since birth. We report, as well, outcomes during therapy for both patients. The information obtained suggests that the disease starts in utero and is characterized primarily by neuromuscular symptomatology (hypotonia, sluggishness, psychomotor delay, absent tendon reflexes, delayed myelination). The laboratory abnormalities are markedly increased creatine kinase and elevated aminotransferases, as well as specific amino acid aberrations that pinpoint the aetiology. The latter include, most importantly, markedly elevated plasma AdoHcy. Plasma S-adenosylmethionine (AdoMet) is also elevated, as is methionine (although the hypermethioninaemia may be absent or nonsignificant in the first weeks of life). The disease seems to be at least to some extent treatable, as shown by improved myelination and psychomotor development during dietary methionine restriction and supplementation with creatine and phosphatidylcholine.

Cytochrome c oxidase partial deficiency-associated Leigh disease presenting as an extrapyramidal syndrome.

Leigh disease is a subacute neurodegenerative disorder characterized by symmetric necrotic lesions in the basal ganglia, cerebellum, thalamus, brain stem, and optical nerves and caused by altered oxidative phosphorylation. We describe the clinical, biochemical, neuroimaging, and molecular studies of a 19-year-old boy with early-onset Leigh disease manifesting as severe extrapyramidal disorder with generalized dystonia and choreoathetosis. He was born of healthy parents after an uneventful pregnancy and delivery. At the age of 2 1/2 years, after a minor respiratory infection, he developed unstable, broad-based gait and tremor of the hands. These symptoms persisted for the next several years, when ataxia became more prominent. Difficulty in swallowing, dysarthria, trunk dystonia, and marked dyskinesia of the arms and hands gradually developed. Nystagmus, transient ptosis, and strabismus also appeared. Abnormal laboratory findings included elevated plasma and cerebrospinal fluid lactate and pyruvate, with an abnormal lactate/pyruvate ratio. Cranial computed tomography and magnetic resonance imaging demonstrated signs of cerebellar atrophy, bilateral and symmetric hypodensities in the lentiform nucleus and thalamus, and transient hyperintensities of cerebral peduncles in T2-weighted sequences suggestive of Leigh disease. Muscle biopsy revealed isolated fiber atrophy, necrotic fibers undergoing phagocytosis, and no ragged-red fibers. The measured catalytic activity of cytochrome c oxidase in skeletal muscle homogenates demonstrated a partial cytochrome c oxidase deficiency No abnormalities in the mitochondrial genome and in the SURF-1 gene were found. The boy is currently receiving levodopa therapy, creatine monohydrate, and a high dosage of thiamine and lipoic acid, his condition is stabilized, and extrapyramidal symptoms are less pronounced.

Inborn errors of metabolism at the turn of the millennium.

Great progress has been made in the field of hereditary metabolic diseases since the beginning of the past century, when metabolic disorders were not really understood and could only be clinically described. Due to the development of basic sciences and advances in technology, we gained insight in the biochemical and molecular basis of hereditary metabolic diseases. It opened possibilities for their treatment, and also led to the discovery of more metabolic diseases, so today, there are more than 500 inborn errors of metabolism known. Although each of these diseases is quite rare, as a group, however, they affect about 1-2% of newborns and therefore pose a significant health problem. The realization about 50 years ago that some hereditary diseases are curable if timely diagnosed led to the introduction of newborn screening in most countries. Modern technologies in this field allow early diagnosis of more than 30 inborn errors of metabolism. Nevertheless, to diagnose most patients correctly, both selective screening involving teamwork and proper use of current technology are required. In addition to considerable development of diagnostic possibilities, the past decade was marked by advances in the therapy of inborn errors of metabolism. A number of clinical trials are currently underway, promising new and more effective approaches in the treatment of these patients. Thus, the field of inborn errors of metabolism at the beginning of the new millennium continues to be a scientific challenge to modern medicine.

Determination of urine saturation with computer program EQUIL 2 as a method for estimation of the risk of urolithiasis.

To investigate the risk for the development of urolithiasis in 30 children with urolithiasis, 36 children with isolated hematuria, and 15 healthy control children, 24-h urinary excretion of calcium, sodium, oxalate, citrate, sulfate, phosphate, magnesium, urate, chloride, ammonium, and glycosaminoglycans was determined and urine saturation for calcium oxalate was calculated with the computer program EQUIL 2. Compared with controls, children with urolithiasis had significantly increased calcium excretion, oxalate excretion, and urine saturation, whereas children with isolated hematuria had significantly increased calcium excretion only. The best estimation of the relative risk of urolithiasis can be made after urine saturation, using logistic regression. The percentage of patients correctly classified after urine saturation is 85.41% in comparison with 80.95% and 73.81% when the estimation was done by calcium excretion and oxalate excretion, respectively. Using the breakpoint value of 4.29 for urine saturation, it was possible to separate children with increased risk of urolithiasis development from the group of children with isolated hematuria.

[Mucolipidosis type III (case report)]. / Mukolipidoza tip III (prikaz bolesnika).

A six-year-old boy with mucolipidosis type III or pseudo Hurler polydystrophy is described. The disease is manifested by multiple progressive joint contractures, especially of fingers, presenting as claw hands. The diagnosis of mucolipidosis was established after exclusion of rheumatoid arthritis and mucopolysaccharidosis. In serum and medium of cultured skin fibroblasts, high catalytic activities of several lysosomal enzymes with strikingly decreased values in fibroblast homogenate were found. In most lysosomal diseases gene mutations cause reduced or absent activity of a specific enzyme. In mucolipidosis type III, a basic biochemical disorder is the absence of mannose-6-phosphate, a marker that enables lysosomal membrane receptors to recognize lysosomal enzymes. The transport of lysosomal enzymes across the lysosomal membrane is therefore defective. These and several other metabolic diseases are thus categorized as the disorders of the lysosomal enzyme transport. A genetic and biochemical heterogeneity, as well as clinical manifestations, are described in more detail.

Acute upper respiratory tract infections and indications for tonsillectomy in children. I. Immunoglobulin synthesis in the palatine tonsil tissue.

Current viewpoints and practice concerning indications for tonsillectomy are presented. The annual specific risk for upper respiratory infection in children aged up to 15 is 1.1. The risk is higher in the youngest age group, in whom it rises to 1.8, decreasing with age and being lowest among children aged 12-15 years (0.5). The proportion of tonsillitis among acute upper respiratory tract infections is highest in the age group up to 3 years (36.9%); at the age of 4-5 years it is 37.1%, and is lowest among children aged 12-15 years (21.9%). The risk of tonsillitis caused by streptococci is highest among children aged up to 5 years. Statistical significance of differences in the synthesis of immunoglobulins (G, M, A and sA) and lysozymes in the palatine tonsil tissue of tonsillectomized children and healthy volunteers was tested by non-parametric tests for independent samples. Significant differences of the above mentioned syntheses were found in all entities studied. Any contribution to the documentation on the nature and cause of each tonsillitis in childhood is of great clinical value, because it is the only basis for rational consideration of indications for tonsillectomy.

Apolipoprotein E phenotypes and genotypes as determined by polymerase chain reaction using allele-specific oligonucleotide probes and the amplification refractory mutation system in children with insulin-dependent diabetes mellitus.

The frequency of apolipoprotein E (apo E) phenotypes and genotypes due to allelic variation at amino acids 112 and 158 was analysed in 50 children with type I diabetes. Phenotypes were determined by isoelectric focusing and genotypes by the technique of polymerase chain reaction using allele-specific oligonucleotide probes (PCR/ASO) and the amplification refractory mutation system (ARMS). Discrepancies between phenotypes and genotypes as assigned by PCR/ASO were observed in 12 (24%) cases and by ARMS in eight (16%) cases. Results revealed the apo E3/3 genotype, as assigned by ARMS, to be the most frequent one (70%), followed by apo E3/4 in 16%, apo E2/2 in 2%, apo E2/3 in 8%, apo E2/4 in 2% and apo E4/4 in 2% of the cases. Apo E3/4 genotype and phenotype were more frequently present in the children with type I diabetes as compared with the diabetic adults previously reported on.

Lipid-bound sialic acid, prostaglandin E and histamine in head and neck cancer.

Blood concentration of lipid-bound sialic acid (LBSA), prostaglandin E (PGE) and histamine were determined in 37 patients with carcinoma of hypopharynx and larynx (supraglottic and glottic), in 12 non-cancer patients and in 10 healthy subjects. The concentration of LBSA was significantly increased in 94.4% cancer patients preoperatively and fell to somewhat lower levels within 1 month after tumour resection. In patients with complete tumour resection and no tumour recurrences within 2 years, it steadily decreased thereafter, reaching normal levels within 6-24 months after surgery, whereas in patients with tumour recurrences or incomplete tumour resection it rose again within 6 months after tumour resection. Similarly, the concentration of PGE was significantly increased in about two thirds of cancer patients (67.6%) preoperatively, dropped significantly within 1 month after tumour resection and rose again in patients with tumour recurrences. Preoperative histamine concentration was decreased in 24.3% of cancer patients and postoperatively it rose both in patients with or without tumour recurrences.

[Gangliosides in the serum in lung carcinoma]. / Serumski gangliozidi kod karcinoma pluca.

In this study, tumor and serum gangliosides were analyzed in patients bearing lung planocellular carcinoma (LPC) before and after operative therapy. Tumor tissue, pathohistologically characterized as carcinoma planocellulare corneum (Ca. epidermoide, type 8070/3, WHO, Geneva, 1981), showed an elevated concentration of gangliosides in comparison to normal tung tissue. The composition of gangliosides in LPC tissue varied from one tumor sample to another, however, two general features were observed. First, LPC contained an increased amount of GM3 and a decreased amount of GD3 gangliosides. Second, an elevated proportion of gangliosides migrating as polysialogangliosides (x3, x5, x6) characterized the majority of LPC tissues. On the other hand, serum of patients with LPC contained an elevated amount of gangliosides (15.8 +/- 0.3 mumols/L) in comparison to control serum (6.1 +/- 0.8 mumols/L) (P less than 0.01). However, analyzing the composition of serum gangliosides by thin-layer chromatography, all serum gangliosides were more or less elevated. By day 21 after the surgical removal of LPC, serum gangliosides dropped by approximately 50% approaching the normal values. It seems that elevated serum gangliosides in LPC patients were secreted from carcinoma cells, because they normalized after surgical removal of LPC. Thus, serum gangliosides might be a useful biochemical tool for diagnosis and therapy monitoring of this carcinoma.