Molecular analysis of 30 mucopolysaccharidosis type I patients: evaluation of the mutational spectrum in Italian population and identification of 13 novel mutations.

Mucopolysaccharidosis type I (MPS-I orMPS1) is an autosomal recessive condition characterized by a broad range of clinical symptoms. Molecular diagnosis of MPS-I is important for analyzing genotype-phenotype correlation and for selecting patients for innovative therapies. In this study we analyzed 30 Italian MPS-I patients with different phenotypes (20 severe, 6 intermediate, 4 mild) in an attempt to recognize the mutational spectrum in our population and to identify major DNA alterations specific to our country. We identified 93% of mutated alleles (56 out of 60) with the reconstruction of the complete genotype in 26 patients out of 30. Twenty-three different mutations were found, 13 of which are novel while the remaining 10 have been already described. Among the novel mutations we found 5 non conservative missense mutations (A160D, E178K, P183R, G197D, D349Y), one nonsense mutation (C53X), 6 deletions (468-470del3, 486-491del6, 755-759del5, 1251delC, 1839-1867del29, 1902-1903del2), and one splice site mutation (IVS11+5G>A). No common mutation for MPS-I is present in our country. Frequently (40% of the alleles), mutations were found in just one or two patients. However, Q70X, P533R, G51D, and W402X mutations were present in several patients (15%, 13.3%, 13.3%, and 11.6% of the alleles respectively) suggesting a Mediterranean origin of the P533R and G51D mutations. In most cases the patients' genotypes were unique combinations of mutations. The great heterogeneity found in our MPS-I population hampers mutation detection and hinders the genotype-phenotype correlation.

Biochemical and genetic defects underlying human congenital hypotransferrinemia.

INTRODUCTION: Human congenital hypotransferrinemia is a rare disorder characterized by the virtual absence of transferrin in the serum. No information on the causes of the disease is known. MATERIALS AND METHODS: Here we describe the identification of a new case, its treatment and the biochemical and genetic defects underlying the disorder. RESULTS: At diagnosis the patient had serum Tf levels equal to about 1% of the normal values. The treatment with plasma infusions each month allowed a good erythropoiesis and the prevention of iron overload with no need of red blood cell transfusions or iron chelators. In order to define the genetic basis of the disease, we performed a haplotype analysis of the Tf gene region in the 26 individuals forming the proband's family, and demonstrated that the genetic defect is located in the Tf gene and that it is inherited as a recessive trait. Protein analyses indicate that the proband serum contains two transferrin forms: one of 80 kD analogous to the normal one, and a smaller one of 50 kD, which may arise from a specific degradation or be the gene product of a modified allele. CONCLUSION: These data suggest the presence of two Tf alleles carrying genetic defects that cause two distinct abnormalities. One allele causes low expression of an apparently normal protein that probably allowed the survival of the patient in the first years of age. The other allele produces a modified Tf with different biochemical characteristics compared to the normal one.

Allogeneic bone marrow stem cell transplantation following CD34+ immunomagnetic enrichment in patients with inherited metabolic storage diseases.

T-cell depletion is an essential step in reducing the risk of graft-versus-host disease (GVHD) in patients with inherited metabolic storage diseases (IMSD) undergoing hematopoietic stem cell transplantation. This goal can be achieved either by selective removal of T cells or by positive selection of CD34+ cells. Large-scale preparations of purified CD34+ cells from bone marrow products have not been extensively described. We report our results with bone marrow CD34+ cell enrichment using the CliniMACS system in eight children with IMSD. The median recovery of positively selected CD34+ cells was 46.2% with a purity of 97.5%, and a residual T cell content of 0.04 x 10(6). A median of 5.5 x 10(6)/kg of CD34+ cells was infused. All patients engrafted at a median time of 12 days and none of the patients developed GVHD. This method is technically feasible and can be successfully used to transplant children with IMSD.

[Gallstone ileus]. / L'ileo biliare.

Gallstone ileus is a rare condition whose diagnosis may be difficult. From January 1976 to December 1991 4 cases of gallstone ileus were treated in our hospital, representing 1% of all patients admitted with mechanical bowel obstruction during that period. Three patients were treated by enterolithotomy alone to remove the impacted stone. In one patient intestinal resection of the bowel tract was associated followed by end to end anastomosis. One patient died (33%) seven days after surgery for cardiopulmonary failure. In one patient the obstruction resolved with the passage of a stone per rectum. The Authors conclude that enterolithotomy alone should be the standard procedure for gallstone ileus. The repair of cholecyst-enteric fistula should be done later only if there are continuing or recurrent symptoms.

Stimulatory effect of naloxone on plasma cortisol in human: Possible direct stimulatory action at the adrenal cortex.

UNLABELLED: The purpose of the present study was to gain a better insight in the mechanism of naloxone underlying the regulation of adrenal cortisol secretion in humans in vivo; therefore, the stimulatory effect of naloxone on cortisol secretion was assessed in a group of patients with hypothalamo-pituitary disconnection. Patients with hypothalamo-pituitary disconnection because of various pathologies (craniopharingioma, cordoma, suprasellar meningioma, or pituitary macroadenoma) participated in the study. RESULTS: Circulating cortisol, but not adrenocorticotropin (ACTH) levels were significantly higher after naloxone administration than after saline. CONCLUSION: Besides the well-known hypothalamo-pituitary stimulatory action on ACTH release in normal humans, the results of the present study suggest that naloxone exerts direct effects on cortisol secretion at the adrenal gland level; another possibility is that naloxone stimulation of cortisol secretion is mediated by other factor than ACTH.