Niemann-Pick type C disease: a novel NPC1 mutation segregating in a Greek island.

Niemann-Pick type C (NPC) disease is a rare autosomal recessive lysosomal storage disease, exhibiting an extremely heterogeneous clinical phenotype. It is a cellular lipid trafficking disorder characterized by the accumulation in the lysosomal/late endosomal system of a variety of lipids, especially unesterified cholesterol. So far two genes, NPC1 or NPC2, have been linked to the disorder. It is a panethnic disease for which two isolates have been described. We present a novel NPC1 mutation (p.A1132P; c.3394G>C) identified in homozygosity in two patients originating from the same small town of an Aegean Sea island and the results of the broad screening of their extended families. Overall 153 individuals have so far been investigated and a total of 64 carriers were identified. Moreover a common descent of the individuals tested was revealed and all carriers could be traced back to a common surname, apparently originating from a common ancestor couple six generations back. The mutation was found associated with an uncommon haplotype in the island that is also present in other populations.

Evolution of Fabry disease in male patients: the Greek experience.

Fabry disease is a progressive metabolic disorder with a clinical course characterized by different phases and a variety of disease manifestations. The first symptoms generally appear in childhood or early adolescence and are followed by late life-threatening complications involving vascular, renal, cardiac, and cerebral systems. We report the clinical and biochemical characteristics of 16 male patients from 10 unrelated families who represent almost the entire cohort of known Fabry patients in Greece. Despite the presence of early symptoms in almost every patient (mean age at onset of symptoms 15.6 years), the diagnosis was delayed for a mean of about 18 years (mean age of diagnosis 36 years). Patients are currently monitored and the majority (15 out 16 patients) treated with Enzyme Replacement Therapy.

Chitotriosidase plasma activity in nephropathic cystinosis.

Chitotriosidase is a fully active chitinase produced and secreted by activated phagocytes. Plasma chitotriosidase activity is a well-established marker of total disease burden in Gaucher disease that has proved useful in monitoring the response to both enzyme replacement and substrate reduction therapies in patients with Gaucher disease. Increased chitotriosidase plasma activity has also been observed in several other lysosomal and non lysosomal disorders. Cystinosis, a rare multisystemic lysosomal storage disease, is characterized by the intralysosomal accumulation of free cystine in many cell types including phagocytes. We here report on plasma chitotriosidase activity in a child with nephropathic cystinosis. Increased plasma chitotriosidase activity (481 nmol/h per ml; normal range 0-150 units) was found on diagnosis and prior to the initiation of oral cysteamine (Cystagon) treatment. Serial estimations of plasma chitotriosidase activity showed that it correlated with leukocyte cystine content and decreased to 100 nmol/h per ml following 14 months' treatment. This novel observation suggests that cystinosis should be included in the differential diagnosis of disorders associated with increased plasma chitotriosidase activity. Furthermore, it suggests that serial estimations of plasma chitotriosidase activity could be of value in monitoring the response to oral cysteamine treatment in cystinosis.

Different pathophysiological mechanisms of intramitochondrial iron accumulation in acquired and congenital sideroblastic anemia caused by mitochondrial DNA deletion.

Sideroblastic anemias (SA) are characterized by iron accumulation in the mitochondria of erythroblasts. Although we have evidence of mitochondrial gene alterations in sporadic congenital cases, the origin of acquired forms [refractory anemia with ring sideroblasts (RARS)], is still largely unknown. Here, we report the analysis of respiratory chain function in a patient with a large mitochondrial deletion and in patients with RARS. A young boy with SA showed symptoms typical of a mitochondrial disease with metabolic acidosis, muscle weakness and cerebral involvement. His bone marrow DNA was analyzed for the presence of mitochondrial deletions. We found a new mitochondrial (mt)DNA deletion spanning 3,614 bp and including all the mt genes encoding complex IV, plus ATPase 6 and 8, and several transfer (t)RNAs. All tissues analyzed (liver, skeletal muscle, brain, pancreas) showed a heteroplasmic distribution of this mutant DNA. Bone marrow homogenates were obtained from five patients with RARS and from three patients with normal bone marrow and respiratory chain function assayed by spectrophotometric analysis. Cytochrome c oxidase (CCO) activity was greatly reduced in the patient's bone marrow. In contrast, CCO activity and global respiratory chain function were conserved in patients with RARS. We conclude that deficient CCO activity secondary to mtDNA deletions is related to intramitochondrial iron accumulation, as in our patient or in those with Pearson's syndrome, whereas other mechanisms, e.g. nuclear DNA mutations, have to be proposed to be involved in the acquired forms of SA.

Low serum insulin values in children with multiple lesions of granuloma annulare: a prospective study.

BACKGROUND: The relationship between granuloma annularae (GA) and diabetes mellitus (DM) is controversial. OBJECTIVE: To investigate the relationship between multiple lesions of GA and carbohydrate metabolism in children. SUBJECTS AND METHODS: Fifteen children (seven boys, eight girls, mean age 4.8 years) with five or more lesions of GA were evaluated. A personal and family history of DM or other autoimmune diseases was obtained and the glycaemic and insulin response during an oral glucose tolerance test (OGTT) was determined. Thirteen children with a negative personal and family history of DM served as controls for the OGTT and 100 other children as 'clinical controls'. RESULTS: At the 30-min sampling of the OGTT the mean insulin values were comparable in GA children and controls (P=0.1), while the mean glucose values were significantly higher in GA children than in controls (P=0.005). All other insulin values during the OGTT were significantly lower in GA children than in controls, while all other glucose values were comparable in GA children and controls with all indices applied. Eleven out of 15 GA children had a positive family history of DM (73.3% vs. 16% of the clinical controls; P<0.0001). CONCLUSION: Multiple lesions of GA in children are associated with significantly lower serum insulin values than in controls and mildly impaired glucose tolerance.

Dihydrofolate reductase activity in primary brain tumors in children.

PURPOSE: Dihydrofolate reductase is an enzyme involved in cell proliferation and differentiation processes. A cytochemical method was used to detect and quantitate this enzyme at the cellular level in brain tumors in children. MATERIAL AND METHODS: Twenty-six children, aged 1-12 years, with primary brain tumors were studied, eight with medulloblastoma, 10 with glioma, and eight with ependymoma or other tumors. The cytochemical technique was applied on touch preparations performed in the operating room form biopsy specimens. RESULTS: Enzyme activity was apparent as cytoplasmic granules sometimes overlying the nucleus of tumor cells. CONCLUSIONS: Activity of dihydrofolate reductase in the children with medulloblastomas and high-grade gliomas was higher than that reported in leukemic blast cells. In the other brain tumors, low grade gliomas, and ependymomas, the enzyme activity was weaker.

Activity of 5-formyl tetrahydrofolate cyclodehydrase and 5,10-methenyl tetrahydrofolate cyclohydrolase in primary brain tumors in children.

The activity of the enzymes 5-formyl tetrahydrofolate cyclodehydrase and 5,10-methenyl tetrahydrofolate cyclohydrolase has been studied cytochemically in children's primary brain tumors. These enzymes play a significant role in purine biosynthesis. Thirty children, aged 1-12 years, were studied, 12 with medulloblastoma, 14 with glioma grade I-IV, and 4 with ependymoma. The activity of the enzymes was apparent as cytoplasmic granules that sometimes overlie the nucleus of the tumor cells. This coincidence showed that different types of brain tumors exhibit different degrees of enzymic activity, which in some cases correlated positively with the malignant potential of the tumor. Approximately one third of the cases were negative for any activity of these enzymes. The intensity of the staining of 5,10-methenyl tetrahydrofolate cyclohydrolase activity was actually higher than that of 5-formyl tetrahydrofolate cyctodehydrase. The clinical or prognostic significance of these findings remains to be clarified, but we believe that cylochemistry provides a sensitive technique for the detection, localization, and description of these enzymes in brain tumor cells. A clear understanding of the mode of action of these enzymes may contribute to devising novel therapeutic strategies.

Family pattern of idiopathic hypercalciuria and its subtypes.

PURPOSE: We determined the mode of inheritance of idiopathic hypercalciuria and its subtypes. MATERIALS AND METHODS: We evaluated 40 children with symptomatic idiopathic hypercalciuria and 129 of their first-degree relatives (80 parents and 49 siblings). In hypercalciuric individuals in families with at least 2 affected members the type of idiopathic hypercalciuria was determined by the calcium loading test. RESULTS: Of the 40 affected children 19 (47.5%) had 1 or more affected first-degree relatives (23 of 80 parents and 2 of 49 siblings). In all 44 affected members of the 19 hypercalciuric families (19 index cases, 23 parents and 2 siblings) the type of idiopathic hypercalciuria was determined (absorptive in 38 and renal in 6). Study of the pedigree of the 19 families showed that idiopathic hypercalciuria appears to be transmitted as an autosomal dominant trait. With only 1 exception the subtype of disease was specific for members of the same family. CONCLUSIONS: Idiopathic hypercalciuria has a familial or sporadic pattern. In the familial pattern an autosomal dominant inheritance is present. The type of the disease is identical in affected members of the same family. The absorptive subtype is more frequent.

Effect of trimethoprim-sulphamethoxazole in Langerhans' cell histiocytosis: preliminary observations.

Twenty-three children with Langerhans' cell histiocytosis (LCH) have been treated with trimethoprim-sulphamethoxazole (T-S) in a 4-year period. The children are classified in two main groups according to the extent of their disease. Group A includes 16 children with single system disease and group B, seven children with multisystem disease. All patients were treated for 4 weeks to 3 months. The results of treatment are evaluated in terms of response in individual organs involved. All children with single system disease had a good response to the drug. Children with multisystem disease had a good response to some organs but a poorer outcome for the lungs and for the blood. These patients did not respond even to conventional chemotherapy.

Hb Sitia [beta128(H6)Ala-->Val]: an unstable variant with a substitution in the alpha1beta1 interface.

Hb Sitia [beta128(H6)Ala-->Val] was found in a Greek female with slightly reduced red blood cell indices. The abnormal hemoglobin was indistinguishable from Hb A by electrophoresis but eluted after Hb A on cation exchange high performance liquid chromatography. DNA sequence analysis revealed a GCT-->GTT mutation at codon 128, which is predicted to encode an Ala-->Val substitution. This was confirmed by mass spectrometry analyses of the beta-globin chain. Since alanine at beta128(H6) interacts with several amino acids of the alpha1beta1 contact, its replacement by a larger residue results in a mild instability of the molecule and slight modifications of the oxygen binding properties.

Insulin dependent diabetes mellitus (IDDM) and autoimmune thyroiditis in a boy with a ring chromosome 18: additional evidence of autoimmunity or IDDM gene(s) on chromosome 18.

A 4 year 3 month old boy with insulin dependent diabetes mellitus (IDDM), autoimmune thyroiditis, slight mental retardation, facial dysmorphism, and a de novo ring chromosome 18 (deletion 18q22.3-18qter) is described. This unique association of defects could represent a chance association. Alternatively, the clinical features could be the result of the chromosomal aberration. If so, one could speculate that a gene or genes on chromosome 18 might act as a suppressor or activator of the autoimmune process by itself or in concert with other IDDM loci.