Research in cystic fibrosis (first of three parts).

This review describes the major directions in cystic fibrosis research in the 
last nine years. There have been no further reports of cystic 
fibrosis in native African Negroes. It has been generally accepted that 
cystic fibrosis follows simple autosomal recessive transmission. It is difficult, however, 
to explain maintenance of a lethal gene at such high frequency. 
Nothing is known of the chromosomal localization of the trait. At 
present there is no simple and reliable method of heterozygote detection. 
The secretions of patients with cystic fibrosis are often not copious 
but exhibit a peculiar rheologic property. Several groups have emphasized decreased 
water content of cystic fibrosis secretions in the pathogenesis of the 
disease. There is no consistent abnormality of glycoproteins or glycosaminoglycans to 
explain why mucus secretions precipitate and obstruct the organ passages. 