Metabonomics and population studies: age-related amino acids excretion and inferring networks through the study of urine samples in two Italian isolated populations.

The study of two different Italian isolated populations was combined with a metabonomic approach to better understand tubular handling of amino acids. Levels of amino acids and metabolites have been analyzed by Nucleic Magnetic Resonance and expressed as ratio vs urinary creatinine concentration (mmol/mol). For most of the amino acids there is an age-related U shape pattern of excretion, with the peaks during childhood and old age, and a significant reduction in the adult age. Hierarchical cluster analysis has clearly identified three groups clustering the same amino acids: His, Thr and Ala (group one); Gly and Phe (group two) and a third larger one. Results have been further confirmed by factor and regression analysis, and used to confirm and, in some cases, infer new amino acids networks. As a matter of facts, the identification of strong evidences for clustering of urine excretion of several neutral amino acids suggests the predominant impact of relevant and common transporters.

Analysis of the HPRT1 gene in 35 Italian Lesch-Nyhan families: 45 patients and 77 potential female carriers.

BACKGROUND: Lesch-Nyhan (LND) disease is an inborn error of purine metabolism which results from deficiency of the activity of hypoxanthine-guanine phosphoribosyltransferase (HPRT). In the classical form of the disease the activity of the enzyme is completely deficient and the patient has cognitive impairment, spasticity, dystonia and self-injurious behaviour, as well as elevated concentrations of uric acid in blood and urine that leads to consequences such as nephropathy, urinary tract calculi and tophaceous gout. There are disease variants without self-injurious behaviour. In these cases neurological manifestations may vary widely. The HPRT1 gene is located on the X chromosome in position Xq26-27.2, and mutations have been found in quite a large number of patients. OBJECTIVE: Documenting our experience with the diagnosis of LND in 45 Italian patients from 35 nonrelated families and 77 females at risk of being carriers of the condition. DESIGN: Internal review. SETTING: An institute devoted to the investigation and care of patients with rare diseases. RESULTS: In 94% of the LND families gDNA sequencing of the patients was informative while in 6% a cDNA study was required. For the carrier females gDNA sequencing was informative in 71% of the families, 23% required qPCR studies and 6% required segregation studies combined with enzymatic activity testing. Classical cDNA studies proved to be unreliable in carrier females as there is a significant risk of failure to detect the mutated allele. Four novel HPRT1 mutations were found: c.145C>T (p.Leu49Phe), c.112C>T (p.Pro38Ser), c.89_96dup8 (p.Glu33Argfs) and c.506dupC (p.Arg170Thrfs). CONCLUSION: In the diagnosis of LND it is very important to consider all the possible alterations of the HPRT1 gene when searching for mutations especially if no affected male is available. Biochemical assessment of the enzymatic activity of HPRT in an affected male is the ideal starting point for molecular analysis of the gene.

Age-related hearing loss in four Italian genetic isolates: an epidemiological study.

The objective of this study was to estimate the prevalence of hearing impairment in four genetically isolated Italian villages (Carlantino, Campora, Gioi-Cardile, and Stoccareddo), 1682 subjects were recruited from all the individuals participating in a multidisciplinary study. They underwent otoscopy and pure-tone audiometry and completed a questionnaire. The audiological data show that the percentage of impaired people increases with age and in particular becomes relevant aged over 40. For this reason we decided to compare the PTA values of individuals aged 40 or older. The PTA values of Stoccareddo and Carlantino are statistically different from PTAs of the other villages. Campora and Gioi-Cardile, both located within the Cilento National Park, have similar middle-low frequency PTA values while some differences are present at high frequencies. Using pedigrees it was possible to calculate the heritability of the trait. For Carlantino and Gioi-Cardile the percentage of the phenotype variation attributable to genetic variation is not significant, while for Campora the heritability value is 0.49 (p = 0.01) suggesting that genetic factors may have an important role.

Increased serum resistin in adults with prader-willi syndrome is related to obesity and not to insulin resistance.

CONTEXT: Determinants of insulin resistance in Prader-Willi syndrome (PWS) are not completely understood. The discovery of several adipokines with relevant effects on insulin resistance and cardiovascular complications of metabolic syndrome offered new tools of investigation of insulin resistance in PWS. OBJECTIVE: The purpose of this study was to measure serum resistin and mRNA in adipose tissue of patients with PWS, those with simple obesity, and healthy controls and correlate resistin levels with anthropometric and biochemical features. DESIGN: Twenty-eight adult PWS patients, 29 obese patients, and 25 healthy controls were studied. Anthropometric variables were measured and fasting serum and plasma were collected for measurement of resistin, adiponectin, leptin, lipid profile, glucose, and insulin. RESULTS: Serum resistin and resistin mRNA expression in adipose tissue was significantly higher in PWS patients, compared with both healthy lean controls and obese patients. Moreover, on regression analysis resistin was significantly correlated with body mass index, whereas no significant association was found between resistin and homeostasis model assessment index. A weak association between resistin and adiponectin was found in the PWS group only. However, on multivariate analysis only the correlation between resistin and body mass index remained significant. CONCLUSIONS: These results support a link between circulating resistin and obesity in humans but do not support a role for resistin in human insulin resistance.

Quantitative evaluation of the clinical effects of S-adenosylmethionine on mood and behavior in Lesch-Nyhan patients.

UNLABELLED: BACKGROUND, RATIONALE, AND METHODS: Lesch-Nyhan disease is a rare, X-linked disorder due to hypoxanthine phosphoribosyltransferase deficiency. To evaluate reported benefit on mood and behavior obtained by the administration of S-adenosyl-L-methionine in this condition, we developed 2 quantitative evaluation tools, and used them to assess the effects of the drug in our population: the weekly questionnaire and the resistance to self-injurious behavior test. We performed an open-label, dose-escalation trial of the drug on 14 patients. RESULTS: Four patients tolerated the drug and reported beneficial effects. The majority experienced worsened behavior. The 2 assessment tools demonstrated effectiveness in quantitatively evaluating the self-injurious behavior.

Specific treatment of Prader-Willi syndrome through cyclical rehabilitation programmes.

PURPOSE: To evaluate retrospectively the efficiency of our rehabilitation programme for patients with Prader-Willi Syndrome. In total, 49 patients were examined, 21 female and 28 male, the youngest in their late teens. Prader-Willi syndrome is generally characterised by cognitive impairment, behavioural abnormalities, and hyperphagia. Patients are usually considerably adverse to any form of physical exercise, and despite hormonal therapy, weight control in adult patients can be difficult. METHODS: Four times a year, disease-specific residential programmes were organised, each lasting 4 weeks. The patients were restricted to a 1500 Kcal diet. In addition, they were required to do 6.5 h of physical exercise daily, stamina being built up by using music therapy, psychomotor therapy, education and entertainment activities. RESULTS: BMI decreased by 2.1 average points in every residential session. For three patients who attended our treatments regularly, a reduction of 8.9 points over 6 years was recorded. An attendance of at least three sessions per year seemed to be necessary to substantially reduce weight. CONCLUSIONS: A multidisciplinary approach and a daily calorie-counted diet can lead to significant weight loss in teenage and adult PWS patients. This approach would also be suitable in treating patients with other obesity syndromes with mental retardation.