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Biomedical subjects

Giuseppe Castaldo

Publications and source records attributed to Giuseppe Castaldo.

16 recordsLinked to original sources

Phenotypic discordance in three siblings affected by atypical cystic fibrosis with the F508del/D614G genotype.

We report an example of atypical CF, i.e., a family in which three siblings were affected by late-diagnosed mild CF, and showed discordant pulmonary and pancreatic phenotypes. Sibling no. 1 (male), showed a severe pulmonary involvement and pancreatic sufficiency; sibling no. 2 (female) showed a mild pulmonary disease with pancreatic sufficiency; sibling no. 3 (male) had a very mild pulmonary expression and pancreatic insufficiency. The sweat test was altered in all three siblings, and all had intestinal occlusion in young age. The whole scanning of CFTR revealed the rare F508del/D614G genotype. The discordance of clinical expression within the same family reinforces the putative role of modifier genes of CF phenotype.

Age of Onset↗

Isolated elevated sweat chloride concentrations in the presence of the rare mutation S1455X: an extremely mild form of CFTR dysfunction.

Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) have been shown to cause typical cystic fibrosis (CF) and several milder phenotypes. We report on two asymptomatic sisters who had isolated increased sweat chloride concentrations, and in whom systematic scanning of the whole coding region of the CFTR gene revealed the F508del/S1455X genotype.

Adult↗

Phenotypic expression of genotype-phenotype correlation in cystic fibrosis patients carrying the 852del22 mutation.

Currently, more than 1,000 mutations have been identified in the cystic fibrosis transmembrane regulator (CFTR) gene. While some mutations are common worldwide, the majority are restricted in certain ethnic groups. We have found that in Southern Italy, the 852del22 mutation is well represented with a frequency of 3.5%. We have screened, by reverse dot blot, denaturing gradient gel electrophoresis (DGGE), and gene sequencing, the entire coding regions of CFTR gene in 371 consecutive cystic fibrosis (CF) patients from Southern Italy and have identified 17 patients carrying rare genotypes, among which 13 [6 M; median age 21.7 years (range: 4.5-47.7 years)] carry the 852del22 mutation. To assess the phenotypic expression of CF in patients with the 852del22 mutations we have compared these patients with a group of age and gender matched patients homozygous for the DeltaF508 mutation [n = 34; 19 M; median age 19.9 years (range: 3.8-34.6 years)]. Overall, we found no difference in terms of complications, patient survival (17.6% vs. 30.7%; P = NS), estimated time needed to develop a severe lung disease (22.1 vs. 24.5 years; P = NS), nutritional status, and rate of infection or colonization by most common pathogens between patients in the two groups. Finally, we have found that a late diagnosis was associated with a poor outcome (severe lung disease) regardless of genotype. Our data show that 852del22 mutation results in a phenotypic expression of disease as severe as that determined by the more typical DeltaF508 and, as in the latter case, there is no strict genotype/phenotype correlation.

Adolescent↗

Distribution of human beta-defensin polymorphisms in various control and cystic fibrosis populations.

Human beta defensins contribute to the first line of defense against infection of the lung. Polymorphisms in these genes are therefore potential modifiers of the severity of lung disease in cystic fibrosis. Polymorphisms were sought in the human beta-defensin genes DEFB1, DEFB4, DEFB103A, and DEFB104 in healthy individuals and cystic fibrosis (CF) patients living in various European countries. DEFB1, DEFB4, and DEFB104 were very polymorphic, but DEFB103A was not. Within Europe, differences between control populations were found for some of the frequent polymorphisms in DEFB1, with significant differences between South-Italian and Czech populations. Moreover, frequent polymorphisms located in DEFB4 and DEFB104 were not in Hardy Weinberg equilibrium in all populations studied, while those in DEFB1 were in Hardy Weinberg equilibrium. Sequencing of a monochromosomal chromosome 8 mouse-human hybrid cell line revealed signals for multiple alleles for some loci in DEFB4 and DEFB104, but not for DEFB1. This indicated that more than one DEFB4 and DEFB104 gene was present on this chromosome 8, in agreement with recent findings that DEFB4 and DEFB104 are part of a repeat region. Individual DEFB4 and DEFB104 PCR amplification products of various samples were cloned and sequenced. The results showed that one DNA sample could contain more than two haplotypes, indicating that the various repeats on one chromosome were not identical. Given the higher complexity found in the genomic organization of the DEFB4 and DEFB104 genes, association studies with CF lung disease severity were performed only for frequent polymorphisms located in DEFB1. No association with the age of first infection by Pseudomonas aeruginosa or with the FEV1 percentage at the age of 11-13 years could be found.

Analysis of Variance↗

Molecular genotyping of the Italian cohort of patients with hemophilia B.

BACKGROUND AND OBJECTIVES: The aim of the study, funded by the Italian Ministry of Health, was to identify the causative mutation in all known patients with hemophilia B in Italy. DESIGN AND METHODS: Overall, 269 patients followed by 25 regional centers were considered in the study; after exclusion of the related individuals, 238 unrelated patients were analyzed (153 with severe, 59 with moderate and 26 with mild hemophilia B). Screening of the factor IX gene was performed using conformation sensitive gel electrophoresis (CSGE) followed by denaturing high performance liquid chromatography (dHPLC) or direct sequencing in negative cases, or by dHPLC/sequencing (36 cases). RESULTS: A mutation was identified in 236 of the 238 patients: 6 had large gene deletions (4 total and 2 partial), 14 small deletions, 1 combined deletion/insertion and 215 single nucleotide substitutions. A correlation was observed between the type of mutation and severity of hemophilia; however, a number of patients with the same genotype had varying severities of the disease. Eight of the 169 patients with severe hemophilia B (4.7%) developed inhibitors: 2 of these had a complete gene deletion, 1 had a large partial deletion (from exon A to part of exon H) while 5 had 3 different nonsense mutations. One patient with a nonsense mutation developed anaphylaxis. We also studied 65 families with hemophilia B involving 144 females (14 obligatory carriers, 85 carriers and 45 non-carriers) and performed 12 antenatal diagnoses. INTERPRETATION AND CONCLUSIONS: The data have been used to build the Italian mutation database to provide each family with knowledge of the disease-causing defect for genetic counseling. This Italian study confirms the marked heterogeneity of factor IX mutations in the population and the presence of a degree of genotype/phenotype discordance. The identification of the mutation can also be used to predict risk of inhibitor development.

Autoantibodies↗

Thromboembolic events and haematological diseases: a case of stroke as clinical onset of a paroxysmal nocturnal haemoglobinuria.

Some haematological diseases are associated to an increased risk of thromboembolic events. We report a case of paroxysmal nocturnal haemoglobinuria (PNH) in which a cerebrovascular event represented the first clinical manifestation of disease. PNH is associated to thromboembolic events, generally of venous districts often involving unusual locations such as mesenteric vessels, sagittal veins, inferior vena cava and renal veins.To our knowledge arterial thrombotic episodes are rare and the involvement of arterial cerebral vessels is exceptional. Then, our case points out the importance of investigating about haematological disorders in all patients presenting with a stroke, in which the common predisposing conditions are excluded.

Journal Article↗

Congenital and acquired thrombotic risk factors in lymphoma patients bearing upper extremities deep venous thrombosis: a preliminary report.

BACKGROUND: Congenital thrombotic risk factors, oncological diseases and its therapies have been related to an increased occurrence of upper extremities deep venous thrombosis (UEDVT). PATIENTS AND METHODS: We studied seven patients bearing lymphoma (one Hodgkin's and six non-Hodgkin's) who developed UEDVT, one at diagnosis and six during chemotherapy (two of these six cases had implantation of a central venous catheter and four received Growth Colony Stimulating Factors in addition to chemotherapy). Patients were screened for: factor V G1691A (Leiden), prothrombin G20210A, methylene tetrahydrofolate reductase (MTHFR) C677T mutations and antithrombin III, proteins C and S plasma activity. RESULTS: All patients were wild-type homozygotes for G20210A. One was heterozygote for factor V G1691A, the other 6 were wild-type homozygotes. Three of the 7 patients were homozygotes and 2 heterozygotes for the MTHFR mutation; the remaining 2 were wild-type homozygotes. Clotting inhibitor levels were normal in all patients. CONCLUSIONS: UEDVT in patients bearing haematological malignancies can occur irrespective of congenital thrombophilic alterations. However, in a subgroup of patients UEDVT could also depend on congenital thrombophilic alterations. A screening for inherited thrombophilia can identify high risk patients that could be specifically treated to prevent thrombotic complications.

Journal Article↗

Butyrate as an effective treatment of congenital chloride diarrhea.

BACKGROUND & AIMS: Many therapeutic attempts have demonstrated to be ineffective in reducing the severity of congenital chloride diarrhea and its long-term complications. The short-chain fatty acid butyrate stimulates intestinal water and ion absorption through a variety of mechanisms, including the activation of a parallel Cl-/butyrate and Na+/H+ exchanger. In this case report, we report the therapeutic efficacy of butyrate on an 11-year-old patient affected by congenital chloride diarrhea. METHODS: The efficacy of increasing doses of oral butyrate (from 50 to 100 mg/kg/day) was investigated through the daily evaluation of stool volume, bowel movements, fecal incontinence, serum, and stool electrolytes concentrations. The modifications in transepithelial intestinal ion transport elicited by butyrate were examined by rectal dialysis study. RESULTS: A butyrate dose of 100 mg/kg/day induced a normalization of stool pattern and of serum and fecal electrolytes concentration. The rectal dialysis study demonstrated a proabsorptive effect induced by butyrate on Na+, Cl-, and K+ intestinal transport. Butyrate therapy was well tolerated during the entire 12-month observation period, and the stool pattern and fecal and serum ion concentrations remained stable within the normal ranges. No clinical adverse events or episodes of dehydration requiring hospital care were observed. CONCLUSIONS: Butyrate could be effective in treating congenital chloride diarrhea. It is easily administered, useful in preventing severe dehydration episodes, and may be a promising therapeutic approach for a long-term treatment in this rare and severe condition.

Butyrates↗

Quality assessment in cytogenetic and molecular genetic testing: the experience of the Italian Project on Standardisation and Quality Assurance.

The first Italian national trial of external quality assessment in genetic testing was organised within the framework of the "Italian National Project for Standardisation and Quality Assurance of Genetic Tests". Sixty-eight Public Health Service laboratories volunteered for the trial, which involved molecular genetic tests (cystic fibrosis, beta-thalassaemia, familial adenomatous polyposis coli and fragile-X syndrome) and cytogenetic tests (prenatal and postnatal, the latter included cancer cytogenetics). The response rate was high (88.2%). The level of analytical accuracy was good, i.e., the percentage of laboratories that correctly genotyped all samples was 89.3% for cystic fibrosis, 90.9% for beta-thalassaemia, 100% for familial adenomatous polyposis coli (despite two laboratories did not complete the analysis because the amount of DNA was considered insufficient), and 90.5% for fragile-X syndrome. Written reports differed widely and were judged "inadequate" in over 50% of cases. Most laboratories from the present study already have experience in previous European external quality assessments for at least one genetic test; this can explain the higher analytical accuracy in the Italian external quality assessment with respect to quality control programmes in other countries. Collaborative networks are strongly suggested to improve the quality of the reports.

Cystic Fibrosis↗

Molecular diagnosis of cystic fibrosis: comparison of four analytical procedures.

We compared the analytical accuracy, times, costs and the detection rate of four procedures for the molecular analysis of cystic fibrosis (CF). DNA from 127 subjects bearing different genotypes was tested by denaturating gradient gel electrophoresis followed by sequencing (reference procedure) and, for comparison, by ASO dot-blot (in-house), reverse dot-blot (Innogenetics), ARMS (Zeneca Diagnostics) and OLA-PCR (PE Applied Biosystem). To assess inter-observer variability, all samples were tested twice. To evaluate intra- and between-series variability, two samples were tested twice in each series. All the procedures yielded reproducible results and assigned the correct genotype to each sample. ASO dot-blot is the cheapest procedure but has the longest analytical time (> 24 h) and uses radioactive labeling. It can be adapted to analyze peculiar mutations in specific ethnic groups. ARMS from Zeneca Diagnostics is rapid (4 h), easy to perform, but, except for the AF508 mutation, does not distinguish the homozygote from the heterozygote genotype. It could be used for carrier analysis in families with known mutations. OLA-PCR has the highest detection rate in most ethnic groups, is automated for capillary electrophoresis but requires a high level of operator expertise: it is suitable when collected series of samples are analyzed from large patient cohorts. Reverse dot-blot is easy to perform and can be semiautomated: it can be used as first-line screening test. Given the heterogeneity of CF mutations, commercial kits should be developed to analyze mutations peculiar to specific ethnic groups.

Cost-Benefit Analysis↗

Haemophilia B: from molecular diagnosis to gene therapy.

Thanks to its typical expression, haemophilia can be identified in writings from the second century AD. Haemophilia B, an X-linked recessive bleeding disorder due to factor IX (FIX) deficiency, has an incidence of about 1:30,000 live male births. The factor 9 (F9) gene was mapped in 1984 on Xq27.1. Haemophilia is diagnosed from prothrombin time, activated partial thromboplastin time, and FIX levels. Carrier females are usually asymptomatic and must be identified only with molecular analysis. Linkage analysis of F9 polymorphisms is rapid and inexpensive but limited by non-informative families, recombinant events, and the high incidence of germline mutations; thus, various procedures have been used for the direct scan of F9 mutations. We set up a novel denaturing high performance liquid chromatographic procedure to scan the F9 gene. This rapid, reproducible procedure detected F9 mutations in 100% of a preliminary cohort of 18 haemophilia B patients. Parallel to the development of more efficient diagnostic tools, the life expectancy and reproductive fitness of haemophilic patients have greatly improved and will continue to improve thanks to the use of less immunogenic recombinant FIX. Hopefully, new approaches based on gene therapy now being evaluated in clinical trials will revolutionise haemophilia B treatment.

Factor IX↗

Genotype-phenotype correlation in cystic fibrosis: the role of modifier genes.

More than 1,000 mutations have been identified in the cystic fibrosis (CF) transmembrane regulator (CFTR) disease gene. The impact of these mutations on the protein and the wide spectrum of CF phenotypes prompted a series of Genotype-Phenotype correlation studies. The CFTR genotype is invariably correlated with pancreatic status-in about 85% of cases with pancreatic insufficiency and in about 15% of cases with pancreatic sufficiency. The correlations between the CFTR genotype and pulmonary, liver, and gastrointestinal expression are debatable. The heterogeneous phenotype in CF patients bearing the same genotype or homozygotes for nonsense mutations implicated environmental and/or genetic factors in the disease. However, the discordant phenotype observed in CF siblings argued against a major role of environmental factors and suggested that genes other than CFTR modulate the CF phenotype. A locus that modulates gastrointestinal expression was identified in mice and subsequently in humans. By analyzing nine CF patients discordant for meconium ileus we were able to show that this locus had a dominant effect. Moreover, in a collaborative study we found a higher rate of polymorphisms in beta-defensin genes 1 and 2 in CF patients and in controls. In another multicenter study mutations in alpha-1 antitrypsin (A1AT) and mannose binding lectin genes were found to be independent risk factors for liver disease in CF patients. The body of evidence available suggests that the variegated CF phenotype results from complex interactions between numerous gene products.

Animals↗