Neonatal screening of cystic fibrosis: diagnostic problems with CFTR mild mutations.

Newborn screening (NBS) of cystic fibrosis (CF) was implemented throughout the whole of France in 2002, but it had been established earlier in three western French regions. It can reveal atypical CF with one or two known CFTR mild mutations, with an uncertain evolution. The sweat test can be normal or borderline. In Brittany, from 1989 to 2004, 196 CF cases were diagnosed (1/2885 births). The incidence of atypical CF diagnosed by NBS is 9.7% (19 from 196). The outcome of 17 (2 lost of view) has been studied, with 9 other atypical CF cases diagnosed by NBS in two other regions. The follow-up period extends from 0.25 to 19.8 years (NBS implemented in Normandy in 1980) with mean age 4.6 years. The most frequent mild mutation is R117H ISV8-7T (50%). At the time of the last visit, nutritional status is normal. All these CF patients are pancreatic sufficient. Only one patient exhibits respiratory infections, whereas 7 others have them intermittently. Two of them had intermittent Pseudomonas aeruginosa colonization at 2.8 and 6.5 years. Mean Shwachman score is 96.7, mean Brasfield score is 22.8. Eight children have had lung function tests (mean follow-up of 10 years): mean FVC was 99% of predicted, mean FEV1 101%, but one of them has FEV1 of 48%. Predicting the phenotype of these atypical CF patients remains difficult, thus complicating any genetic counselling. A regular clinical evaluation is necessary, if possible by a CF unit, because CF symptoms may appear later.

Comparing the clinical evolution of cystic fibrosis screened neonatally to that of cystic fibrosis diagnosed from clinical symptoms: a 10-year retrospective study in a French region (Brittany).

Until the year 2000, systematic cystic fibrosis (CF) neonatal screening was only performed in a few regions of France. The Brittany region began in 1989, but not the neighboring region of Loire-Atlantique. The present study compares the clinical evolution of both affected populations 10 years after screening was started. Although the 77 screened and 36 nonscreened children were followed in different CF centers, they were included in similar care protocols. The clinical characteristics at diagnosis and their evolution over a 10-year period of all the children affected with CF and born between January 1, 1989 and December 31, 1998, excluding those with meconium ileus, were compared. There were no significant differences in sex ratio, gestational age, anthropometric data at birth, frequency of deltaF508 homozygotes, proportion of pancreatic-insufficient patients, and mean age between the two populations. Age at diagnosis was lower in the screened group (38 days vs. 472 days, P < 10(-7)), as was the delay in supplementation with pancreatic enzymes (1.7 months vs.15.9 months, P < 10(-7)). The proportion of children who were hospitalized at least once was higher among the nonscreened than the screened patients (86% vs. 49%, P < 10(-4)). Z-scores for weight and height were significantly better in the screened population, not only in the first years of life, but also at 5 years old for height and 8 years old for weight. The Shwachman and Brasfield scores were higher among the screened children during the whole period of follow-up. No significant differences in colonization by Pseudomonas aeruginosa nor in lung function were found. Given the homogeneity in the characteristics and the follow-up of both populations, the benefits in terms of nutrition and clinical well-being of neonatal screening appear to be clear, thus confirming the advantages of its general implementation.

[Does neonatal screening of cystic fibrosis affect outcome? Comparative study of two cohorts in Britanny and Loire-Atlantique with follow-up after ten years]. / Le dépistage néonatal systématique améliore-t-il le pronostic de la mucoviscidose? Etude comparative de deux cohortes en Bretagne et en Loire-Atlantique avec un recul de dix ans.

UNLABELLED: Neonatal screening for cystic fibrosis was started in Brittany in 1989 but not in the adjacent department of Loire-Atlantique. This study compares the outcome from the children of both populations nine years after the beginning of the screening. Those children were seen in different centers but with the same following guidelines. POPULATION AND METHODS: All children with cystic fibrosis born between 01/01/89 and 31/12/97 in Brittany and the Loire-Atlantique, excluding the meconium ileus, were compared for their initial characteristics and their outcome after nine years of follow-up. RESULTS: There was no significant difference between both populations for sex ratio, gestational age, birth biometry, percentage of homozygotes delta F508, and mean age of children. Age at diagnosis was lower in Brittany (37 vs 372 days, P < 10(-7)), as was the delay for starting pancreatic supplementation (1.5 vs 14.3 months, P < 10(-7)). Percentage of children hospitalized at least once was higher in Loire-Atlantique (84.4 vs 40.3%, P < 10(-4)). There was no significant difference for colonization with Pseudomonas aeruginosa. Z-scores for weight and height were better in Brittany, as were Shwachman's and Brasfield's scores. CONCLUSION: The homogeneity of both populations and their follow-up points out that even if the numbers of children are small and the study is retrospective, some benefits of neonatal screening appear, which are already found in other countries where it is partly practiced. This leads us recommend its general use in our populations, which should be associated with the follow-up of the screened children in cystic fibrosis centers to achieve the most of its benefits.