Frequency of the deltaF508 mutation in 108 cystic fibrosis patients in Sao Paulo: comparison with reported Brazilian data

Genetic predisposition and its impact on natural history of idiopathic acute and acute recurrent pancreatitis in children

BACKGROUND

Genetic predisposition in paediatric idiopathic acute, acute recurrent pancreatitis and its consequences are unknown. We studied frequency of genetic markers in acute, acute recurrent, chronic pancreatitis and their impact on natural history.

METHODS

Over a period of 2 years 68 consecutive children with pancreatitis (35.3% acute, 32.3% acute recurrent, 32.3% chronic) and 25 controls were recruited in a single centre. Common mutations for serine-protease-inhibitor (SPINK1 N34S), protease-inhibitor (PRSS1 R122H) and cystic fibrosis transmembrane conductance regulator (CFTR DeltaF508, 5T) were analysed.

RESULTS

Mean age was 13.4±2.5 years. Overall, 30 cases (SPINK1 N34S n=26, CFTR 5T n=4) and 1 control (SPINK1 N34S) had mutations (p=0.0001). The prevalence of SPINK1 N34S mutation was similar in chronic and acute recurrent pancreatitis (45%). Six children with severe acute pancreatitis had SPINK1 N34S mutations (25%, p<0.05), and 4 were homozygous. On follow-up 5 acute pancreatitis patients with mutations and 1 without mutations developed chronic pancreatitis (p=0.004); 8 cases of acute recurrent pancreatitis progressed to chronic pancreatitis (38%); of these 66.7% had mutations vs. 16.7% who did not (p=0.03).

CONCLUSIONS

Almost 50% of idiopathic chronic, acute recurrent and 33% of acute pancreatitis in children are genetically predisposed. Presence of genetic mutations in acute and recurrent acute pancreatitis increases the risk of developing chronic pancreatitis.

Cystic fibrosis transmembrane conductance regulator mutations at a referral center for cystic fibrosis

OBJECTIVE

To determine the frequency of six mutations (F508del, G542X, G551D, R553X, R1162X, and N1303K) in patients with cystic fibrosis (CF) diagnosed, at a referral center, on the basis of abnormal results in two determinations of sweat sodium and chloride concentrations.

METHODS

This was a cross-sectional study involving 70 patients with CF. The mean age of the patients was 12.38 ± 9.00 years, 51.43% were female, and 94.29% were White. Mutation screening was performed with polymerase chain reaction (for F508del), followed by enzymatic digestion (for other mutations). Clinical analysis was performed on the basis of gender, age, ethnicity, pulmonary/gastrointestinal symptoms, and Shwachman-Kulczycki (SK) score.

RESULTS

All of the patients showed pulmonary symptoms, and 8 had no gastrointestinal symptoms. On the basis of the SK scores, CF was determined to be mild, moderate, and severe in 22 (42.3%), 17 (32.7%), and 13 (25.0%) of the patients, respectively. There was no association between F508del mutation and disease severity by SK score. Of the 140 alleles analyzed, F508del mutation was identified in 70 (50%). Other mutations (G542X, G551D, R553X, R1162X, and N1303K) were identified in 12 (7.93%) of the alleles studied. In F508del homozygous patients with severe disease, the OR was 0.124 (95% CI: 0.005-0.826).

CONCLUSIONS

In 50% of the alleles studied, the molecular diagnosis of CF was confirmed by identifying a single mutation (F508del). If we consider the analysis of the six most common mutations in the Brazilian population (including F508del), the molecular diagnosis was confirmed in 58.57% of the alleles studied.

Lung transplantation in patients with cystic fibrosis

Cystic fibrosis (CF) an autosomal recessive genetic disorder, affects many organs. The great majority of deaths occur due to respiratory failure after many years of chronic pulmonary infection. Despite recent progress in early detection by studies of genetic mutations and better understanding to treat nutritional and infectious states, lung transplantation is the CF treatment for most advanced cases. According to the International Society for Heart and Lung Transplantation (ISHLT) data, CF is the third most common reason for lung transplantation (16.8%) showing the best survival rate (60% at 5 years). We have described our experience in lung transplantation of CF patients between January 2000 and December 2011, reviewing medical charts of these patients were for gender, age, body mass index (BMI), comorbidities, disease duration, previous sputum gram stain, ischemic time, incidence of severe primary graft dysfunction (PGD Grade 3), intensive care unit (ICU) length of stay, and Kaplan-Meier survival. Among 150 lung transplantation, the 30 CF patients (20%) represented the second most common cause. The average age was 27.4 ± 9.2 years, with a slight predominance of males (n = 16; 53.3%). The average BMI was 18.9 ± 2.6. Most patients (60%) had pancreatic exocrine dysfunction. Also, 83.3% of patients showed a positive sputum culture for Pseudomonas, while Burkholderia cepacia was identified in only 4 patients (13.3%). The average time of the disease was 20.8 ± 9.7 years. All transplantation were bilateral with an average ischemic time of 472 ± 98.3 minutes and ICU length of stay of 9.9 ± 6.3 days. The survival rates at 1 and 5 years were 92% and 77%, respectively, corresponding to the best outcomes among underlying diseases, comparable with other worldwide series and better than the ISHLT reports. CF, the second most common cause for lung transplantation among our cases, showed the best survival rate among all causes. Our survival rate was comparable with other reports.

Williams Syndrome: development of a new scoring system for clinical diagnosis

OBJECTIVE

To develop a scoring system based on clinical findings to assist pediatricians in the diagnosis of William syndrome and to delineate when the fluorescent in-situ hybridization test to detect the microdeletion at 7q11.23 may be needed.

METHODS

The fluorescent in-situ hybridization test was performed on 20 patients presenting William syndrome suggestive clinical features. Eleven studies were selected from the literature in which there were 2 groups: patients with positive or negative fluorescent in-situ hybridization tests. Forty-two clinical characteristics were compared to those reported in the literature to determine which ones were associated with the affected patients (ie, bearing deletions) using meta-analysis. The 2-tailed Fisher exact test were used so that the frequency of findings observed in fluorescent in-situ hybridization positive and fluorescent in-situ hybridization negative patients could be compared in the present study together with the patients from the literature. We developed a scoring system based on clinical findings and their significant associations with patients with positive fluorescent in-situ hybridization tests. From the mean and standard-deviation values of the data from our patients, we determined the cut-off score that that indicated the need for a fluorescent in-situ hybridization test to confirm diagnosis.

RESULTS

Seventeen patients were fluorescent in-situ hybridization positive, and 3 were fluorescent in-situ hybridization negative. The more discriminative findings among fluorescent in-situ hybridization positive patients were the following: typical facies, low birth weight, feeding difficulties, constipation, supravalvar aortic stenosis, mental retardation, and friendly personality. The distribution of the points among the 20 patients ranged from 19 to 28 points with a mean value of 23.3 out of a possible total of 31 points. The cut-off score that indicated the need for a fluorescent in-situ hybridization test was 20.

CONCLUSIONS

Our scoring system enables physicians to differentiate between those individuals who can be reliably diagnosed as having Williams syndrome solely from the clinical findings and those who need to undergo fluorescent in-situ hybridization testing for a correct diagnosis.