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The incidence of cystic fibrosis (CF) can vary significantly among different racial groups; within white populations it has been reported to vary from 1/3419 in the USA to 1/2500 in the UK and 1/4700 in Italy. According to Lewis,1 the highest incidence that can be reliably expected in white populations is 1/2500, although a value as high as 1/936 has been reported in a well defined community.2
Italy and other European countries have experienced a heavy influx of immigrants from Albania in the last 10 years following political and economic upheaval occurring in that country. Although precise numbers are not available, since 1989 some tens of thousands of Albanian immigrants have settled in Tuscany, a region of central Italy populated by 3.5 million people in an area of 23 000 sq km. There are no data on the incidence of CF in Albanians, so we have calculated the incidence of CF in newborn infants of the Albanian community residing in Tuscany.
We analysed the records for the period from 1 July 1991 to 31 December 2001 contained in the database of the Tuscan regional neonatal screening programme for CF which was carried out using the immunoreactive trypsin assay with lactase meconium complementary test, and which covered 99.99% of the newborn infants in the region.3 During the observation period 275 520 newborn infants were screened for CF in Tuscany. On the basis of the information contained in the forms completed at birth by the obstetricians at the maternity wards or at home and checked by the CF Regional Centre, 1803 children were born to both ethnic Albanian parents during this period. The number of Albanian newborns was not constant over the years of the study, but it has grown steadily from 15 in 1991 to 474 in 2001.
During the observation period four cases of CF were diagnosed (by two positive sweat tests) among children born to both Albanian parents (incidence 1/450 (95% confidence intervals (95%CI) 1/176 to 1/1653)) and 60 cases were diagnosed among the 273 717 non-Albanian newborn infants in the region (incidence 1/4592 (95% CI 1/3543 to 1/5977); point estimate ratio 10.12 (95% CI 2.67 to 27.28); p=0.0009). The four Albanian infants with CF were born to parents who were unrelated and who came from different geographical zones of Albania.
To define the incidence of CF correctly it is important that the study is based on a well defined, large population belonging to a precise geographical area and that it covers a sufficiently long period of time.1 We are confident that we have analysed an entire population of immigrants in a well defined geographical zone over a period of 10 years. The CF cases were diagnosed using an appropriate screening programme with good sensitivity.
We are not aware of any factor that could account for the increased incidence of CF in the population studied. There is no evidence to suggest the selection of CFTR mutation carriers among Albanian immigrants to our region. We did not note any selection bias in the cases we observed based on parentage or geographical provenance of immigrants from Albania, since couples were unrelated and came from different regions of the country. The suggestion that parents of Albanian newborn infants with CF emigrated because of the knowledge of being a carrier or because of a prenatal diagnosis can be excluded both on the basis of patients’ anamnesis and considering the poor status of the Albanian health system.
Available publications on Albanian emigration following the political and social upheaval of the early 1990s do not provide any information relating to migratory patterns based on certain geographical zones, familial origins, or cultural level,4 and show a weak correlation between intention to emigrate and income.5
The absence of factors which could have biased the results of our study allow us to hypothesise that there is a high incidence of CF in Albanian people. For a long time Albania had no external migratory fluctuations and had closed social structures with a high incidence of endogamy, remaining politically and socially isolated from the rest of the world.4 These factors may have contributed to a high prevalence of carriers of the CFTR gene in the Albanian population.
Our data call attention to the necessity of studying the incidence of CF among Albanians in their own country. While awaiting these results, physicians should give particular attention to the possibility of CF when caring for ethnic Albanian children.
We thank Telethon Foundation, Italy for its grant EC 1208-2000.
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