Question: What is the incidence of cystic fibrosis in the caucasian population?

Context:
Estimates of the newborn frequency of cystic fibrosis in different Caucasian groups range from 4 times more to 40 times less common than the generally accepted figure of 1:2000.
Current meconium screening trials which may be effective in populations with the incidence equal to or greater than 1:2000, may be useful for populations with an incidence as low as 1:7000 only after maximum improvement of the methods
Studies on migrant Indian population in United States and United Kingdom estimate frequency of CF as 1:10,000 to 1:40,000
The frequency of common mutation F508del in Indian children is between 19% and 34%. Other mutations are heterogeneous
The delta F508 mutation was found in 9 cases (60%), of which 5 were homozygous for the disorder.
The disease frequency varies considerably among the latter. Among Ashkenazi Jews, the frequency of CF is 1:3300, which is similar to the frequency in most Caucasian populations
Although no careful scientific study had ever been done the impression was that CF was extremely rare among the Greek-Cypriots, with an incidence estimated at around 1:30,000
The incidence of cystic fibrosis (CF) in Finland, 1:25,000 newborn, is one of the lowest in Caucasian populations
Cystic fibrosis (CF) is the most common severe autosomal recessive genetic disorder in Caucasian populations, with an incidence of about 1 in 2000 live births, implying a carrier frequency of about 1 in 22
The incidence of cystic fibrosis (CF) in Finland is one tenth that in other Caucasian populations
In Denmark the incidence of cystic fibrosis is 1:4700, which is quite low compared to other European countries.
Cystic fibrosis is the most frequent autosomal recessive disease in the Caucasian population, with an incidence of 1:2500 newborn
Cystic fibrosis (CF) is the commonest autosomal recessive condition among Caucasian populations, affecting 1 in 2500 live births.
Cystic fibrosis (CF) is the most common severe autosomal recessive genetic disorder in Caucasian populations, with an incidence of about 1 in 2000 live births
Cystic fibrosis (CF) is the most common autosomal recessive disorder in the Caucasian population, affecting approximately 1 in 2,000 newborns but the actual estimate varies with the geographic location. 
Cystic fibrosis (CF) is an autosomal recessive disorder with a prevalence at birth estimated at 1/2000-1/2500 livebirths in Caucasian populations
Cystic fibrosis is one of the most common autosomal recessive hereditary diseases in the Caucasian population, with an incidence of 1:2000 to 1:3500 liveborns
Cystic fibrosis (CF) is the most common autosomal recessive disease in the European (Caucasian) population, with an incidence of 1:2000 to 1:8000
Cystic fibrosis (CF) is the most common genetic disease in Caucasian populations, with an incidence of 1 in 2,000 live births in the United Kingdom, and a carrier frequency of approximately 1 in 20
Current meconium screening trials which may be effective in populations with the incidence equal to or greater than 1:2000, may be useful for populations with an incidence as low as 1:7000 only after maximum improvement of the methods. Once the true incidence or the variable incidence is proven for Caucasian populations, screening trails in Negro, Oriental and Indian populations will be required.
Cystic fibrosis (CF) is the most common lethal genetic disease among Caucasian populations. The generally accepted incidence of CF in the United States is 1 in 3,200 in the Caucasian population.
In this region, it has been documented that the incidence of cystic fibrosis reached 1/902 live births between 1975 and 1988, three times higher than the average incidence of 1/2500 live births reported in other Caucasian populations.
Cystic fibrosis (CF) is the most common autosomal recessive disorder in the Caucasian population, affecting approximately 1 in 2,000 newborns but the actual estimate varies with the geographic location. The incidence of CF in non-Caucasian populations is low.
Cystic fibrosis is the most frequent autosomal recessive disease in the Caucasian population, with an incidence of 1:2500 newborn and a frequency of 1:25
Cystic fibrosis (CF) is the most common lethal inherited disease in the Caucasian population with an incidence of approximately 1 in 2,500 live births
Cystic Fibrosis (CF) is the most common and severe autosomal recessive disease in Caucasian populations, with an incidence of 1 in 2500 live births. 

Answer: Estimates of the newborn frequency of cystic fibrosis in different Caucasian groups range from 4 times more to 40 times less common than the generally accepted figure of 1:2000.
Cystic fibrosis (CF) is the most common autosomal recessive disorder in the Caucasian population, affecting approximately 1 in 2,000-1/2,500 live births, but the actual estimate varies with the geographic location.
Exact answer: 1:2000