Rita Barone

DPM2-CDG: A muscular dystrophy-dystroglycanopathy syndrome with severe epilepsy

Congenital disorders of glycosylation (CDG) are a group of metabolic diseases due to defects in protein and lipid glycosylation. We searched for the primary defect in 3 children from 2 families with a severe neurological phenotype, including profound developmental delay, intractable epilepsy, progressive microcephaly, severe hypotonia with elevated blood creatine kinase levels, and early fatal outcome. There was clinical evidence of a muscular dystrophy–dystroglycanopathy syndrome, supported by deficient O‐mannosylation by muscle immunohistochemistry.

Plasma chitotriosidase activity in acute Plasmodium falciparum malaria.

BACKGROUND Chitotriosidase is a functional chitinase secreted by activated macrophages. It is encoded by a gene located on chromosome 1q31-32, whose mutations may be responsible for chitotriosidase deficiency, encountered in almost 6% of Caucasian population. OBJECTIVE This study reports firstly plasma chitotriosidase activity in African children with acute Plasmodium falciparum malaria. The chitotriosidase activity was correlated to objective parameters reflecting the status of the disease and compared with those found in healthy African children. RESULTS We found that plasma chitotriosidase levels are significantly increased in African children with acute malaria (185.0+/-141.0 nmol/h/ml; median 150; range 11-521) with respect to reference values obtained in age matched African children (84.4.5+/-72.8 nmol/ml/h; median 63; range 4-350) (P<0.001). Moreover the levels of chitotriosidase were higher in African children than in Caucasian children matched for age (28.86+/-18.7 nmol/h/ml; median 24; range 1-98) (P<0.0001). A remarkable significant correlation was found between plasma chitotriosidase and reticulo-endothelial activation, as judged by thrombocytopenia degree and serum ferritin level in children with acute malaria. CONCLUSION Based on this study, it appears that genetic and environmental features might be responsible for diversity of plasma chitotriosidase activity in black children living in Burkina Faso.

A 24-bp duplication in exon 10 of human chitotriosidase gene from the sub-Saharan to the Mediterranean area: role of parasitic diseases and environmental conditions

Human chitotriosidase (Chit) is a member of the chitinase family and it is synthesized by activated macrophages. Recently, a genetic polymorphism was found to be responsible for the common deficiency in Chit activity, frequently encountered in different populations. We analyzed the Chit gene in some ethnic groups from the Mediterranean and African areas, to evaluate whether the Chit gene polymorphism correlates with the changes in environmental features and the disappearance of parasitic diseases. We found a heterozygote frequency for the duplication of 24 bp in exon 10 of 44% in Sicily and 32.71% in Sardinia, whereas those homozygous Chit deficient were 5.45 and 3.73%, respectively. In contrast, in Benin and Burkina Faso, both mesoendemic regions for Plasmodium falciparum malaria and other infections due to intestinal parasites, a low incidence of Chit mutation was found (heterozygous 0 and 2%, respectively) and no subject was homozygous for Chit deficiency. Our results provide evidence of the fact that the low frequency or the absence of mutant Chit gene may represent a protective factor in the population still living in disadvantaged environmental conditions. The present study suggests that the disappearance of parasitic diseases and the improved environmental conditions may have ensued the occurrence of a high percentage of 24-bp mutation in Sicily, in Sardinia and in other Mediterranean countries, whereas in the sub-Saharan regions (Benin and Burkina Faso), the widespread parasitic diseases and the poor social status have contributed to maintenance of the wild-type Chit gene.

Phosphomannomutase deficiency is the main cause of carbohydrate-deficient glycoprotein syndrome with type I isoelectrofocusing pattern of serum sialotransferrins

J. JAEKEN1*, J. ARTIGAS2, R. BARONE3, A. FIUMARA3, T. J. DE KONING4, B. T. POLL-THE4, J. F. DE RIJK-VAN ANDEL5, G. F. HOFFMANN6, B. ASSMANN6, E. MAYATEPEK7, M. PINEDA8, M. A. VILASECA8, J. M. SAUDUBRAY9, B. SCHLÜTER10, R. WEVERS11 and E. VAN SCHAFTINGEN12 1Department of Pediatrics, University of Leuven, Belgium; 2Department of Pediatrics, Parc Taulí Hospitals, Sabadell, Spain; 3Department of Pediatrics, University of Catania, Italy; 4Wilhelmina Children’s Hospital, Utrecht, The Netherlands; 5Department of Neurology, Ignatius Hospital Breda, The Netherlands; 6University Children’s Hospital, Marburg, Germany; 7Department of Pediatrics, University of Heidelberg, Germany; 8University Hospital Sant Joan de Déu, Barcelona, Spain; 9Department of Pediatrics, Hôpital des Enfants Malades, Paris, France; 10Vestische Kinderklinik, Datteln, Germany; 11Institutes of Neurology, Pediatrics and Radiology, University Hospital Nijmegen, The Netherlands; 12Laboratory of Physiological Chemistry, ICP and University of Louvain, Belgium

Clinical and neuroradiological findings in classic infantile and late‐onset globoid‐cell leukodystrophy (Krabbe disease)

In the present study the clinical course and imaging of early and late-onset forms of Krabbe disease are analyzed. We report on 11 patients with a biochemical diagnosis of galactosyl ceramide beta-galactoside deficiency. Two presented as the classic infantile form and died within the second year of life. In 9 children the first clinical signs, such as gait difficulties and visual failure, started after age 2 years. All these patients developed slow regression of motor and mental capacities, and most of them died within their first decade. In patients of both groups computed tomography (CT) and magnetic resonance imaging (MRI) were performed. In the late-onset form, hypodensities of the central white matter and pyramidal tracts were the leading radiological signs, whereas in the early-onset form, hyperdensities and cerebellar white matter lesions were also detected. From our results it becomes clear that variability of Krabbe disease refers not only to clinical manifestation but also to CT and MRI findings. Better knowledge of phenotypic and radiological diversity will help to understand the pathogenesis of the disease.

Outcome of psychiatric symptoms presenting at onset of multiple sclerosis: a retrospective study

Psychiatric disturbances may occur at the onset of multiple sclerosis. However, information on their outcome is lacking. Our objective was to document the characteristics of psychiatric symptoms at presentation of multiple sclerosis and to define the long-term evolution of psychiatric disturbances in these patients. Based on a clinical record analysis of patients with defined multiple sclerosis diagnosis and coming under the care of a university multiple sclerosis centre within the period 1997—2007, patients with both psychiatric and neurological symptoms at presentation were identified. Clinical data at onset and at last follow-up were considered. Among 682 evaluated patients, psychiatric disturbances were associated with multiple sclerosis onset in 16 cases (2.3%). Most patients (56%) presented with a mood disorder with clinical characteristics of a major depressive-like episode, five (32%) had psychotic symptoms. Initial psychiatric disturbances improved later than neurological symptoms, or never fully recovered, regardless of the concomitant use of psychotropic medications. In most of the subjects psychiatric disturbances tended to remain over the follow-up period and at last visit, after a mean follow-up of 7.6 years (±2.3), 14 subjects (87%) had a supplementary diagnosis of psychiatric illness. Psychiatric symptoms at onset of multiple sclerosis may be indicators of possible maintenance of psychiatric morbidity in a sizeable proportion of patients.

Multiplexed glycoproteomic analysis of glycosylation disorders by sequential yolk immunoglobulins immunoseparation and MALDI-TOF MS.

This study applied yolk immunoglobulins immunoaffinity separation and MALDI‐TOF MS for clinical proteomics of congenital disorders of glycosylation (CDG) and secondary glycosylation disorders [galactosemia and hereditary fructose intolerance (HFI)]. Serum transferrin (Tf) and α1‐antitrypsin (AAT) that are markers for CDG, were purified sequentially to obtain high‐quality MALDI mass spectra to differentiate single glycoforms of the native intact glycoproteins. The procedure was found feasible for the investigation of protein macroheterogeneity due to glycosylation site underoccupancy then ensuing the characterization of patients with CDG group I (N‐glycan assembly disorders). Following PNGase F digestion of the purified glycoprotein, the characterization of protein microheterogeneity by N‐glycan MS analysis was performed in a patient with CDG group II (processing disorders). CDG‐Ia patients showed a typical profile of underglycosylation where the fully glycosylated glycoforms are always the most abundant present in plasma with lesser amounts of partially and unglycosylated glycoforms in this order. Galactosemia and HFI are potentially fatal diseases, which benefit from early diagnosis and prompt therapeutic intervention. In symptomatic patients with galactosemia and in those with HFI, MALDI MS of Tf and AAT depicts a hypoglycosylation profile with a significant increase of underglycosylated glycoforms that reverses by dietary treatment, representing a clue for diagnosis and treatment monitoring.

Chitotriosidase in Patients with Acute Ischemic Stroke

Background: Following an acute brain ischemia, local endothelia allow monocyte chemoattraction into the lesion site which contributes to brain damage through a group of neurotoxic factors. A relationship exists between the extent of brain damage and the plasma level of monocyte products, including chitotriosidase, though usually strictly related to preexisting infectious-inflammatory diseases. Purpose: Since chitotriosidase activity is also elevated in pathogen-free conditions, we tested whether chitotriosidase upregulation might be specifically related to stroke and unrelated to clinically relevant infectious diseases. Methods: We studied the plasma level of chitotriosidase activity, TNF-α and IL-6 in 44 consecutive patients with acute brain ischemia without concomitant symptoms or signs of inflammatory-infectious diseases. Results were compared with stroke severity and outcome as detected by brain CT and NIH scale. Blood samples were collected, on average, 11 h after stroke onset. Results: Chitotriosidase activity positively correlates with stroke severity, as measured by NIH scale (r = 0.69, p<0.01), to the extent of brain damage as documented by CT (r = 0.75, p ≤ 0.001) and the TNF-α level (r = 0.76, p<0.001); it also inversely correlates with the IL-6 level (r = –0.43, p ≤ 0.05). Conclusion: Our results indicate that chitotriosidase is a specific marker of macrophage activation occurring in stroke which directly correlates with stroke severity independently of preexisting inflammatory or infectious conditions.

Bone ultrasonometry, bone density, and turnover markers in type 1 Gaucher disease

Abstract. In 12 patients (mean age, 33 ± 13 years) with type 1 Gaucher disease (GD), we evaluated bone mass by broadband ultrasound attenuation (BUA) of the calcaneus and dual X-ray absorptiometry (DXA) of the total body, lumbar spine, and hip. In all patients, we measured serum levels of osteocalcin (OC) and bone-specific alkaline phosphatase (BAP) and urinary excretion of pyridinoline (Pyr/Cr) and deoxypyridinoline (D-Pyr/Cr) cross-links. Compared to age- and sex-matched healthy controls, patients with GD showed marked osteopenia at all measuring sites as expected. Values of BUA (67.25 ± 15.83 dB/MHz) were also significantly reduced. OC and BAP concentrations were within the normal range. Pyr/Cr and D-Pyr/Cr were significantly higher than in controls. Calculating T- and Z scores, we found a significant correlation between the Bone Severity Score Index (BSSI) and both BUA and BMD measurements. A significant correlation was also found between pyridinoline urinary excretion and both BSSI and BUA at the calcaneus. Our data suggest that type 1 GD in adulthood is associated with increased bone resorption and that BUA at the calcaneus may be a relevant tool in the assessment of bone status in these patients.

Two new mild homozygous mutations in Gaucher disease patients: Clinical signs and biochemical analyses

Gaucher disease (GD) is a lysosomal storage disorder resulting from impaired activity of lysosomal beta-glucocerebrosidase. More than 60 mutations have been described in the GBA gene. They have been classified as lethal, severe, and mild on the basis of the corresponding phenotype. The fact that most GD patients are compound heterozygous and that most type 1 patients bear the N370S allele, which by itself causes a mild phenotype, make it difficult to correlate the clinical signs with the mutations. Besides N370S, about 10 mild mutations have been described, but only one undoubtedly classified as mild was found at homozygosity. Here we report 2 novel mutations, I402T and V375L, at homozygosity in 2 adult Italian type 1 GD patients. Some properties of the I402T fibroblast enzyme have been compared to those of the enzyme from cells of several N370S/N370S patients. Analysis of the catalytic properties and heat stability as well as the response to phosphatidylserine and sphingolipid activator protein indicate a marked similarity between the 2 enzymes. The finding of another, unrelated patient bearing the I402T mutation (in this case as a compound heterozygote with mutation N370S) suggests that this allele might be quite frequent in the area of Sicily from where both patients originated. In conclusion, the phenotypic expression in the 2 homozygous patients presented here and the biochemical data for one of them allowed the classification of these mutations as mild thus extending the group of mild mutations found at homozygosity.