Ground breaking research aims to cure Primary Ciliary Dyskinesia
Cilia are tiny hair like structures that are found in the lungs, bronchia, and in the reproductive system. They are flexible and belong to the cleaning system of the respiratory tract, where their continuous wave prevents dust and germs from entering. Ciliary dyskinesia also causes the dysmotility or complete immotility of spermatozoa resulting in male infertility. This very rare syndrome with 1 in 30,000 occurrence manifests itself through chest infections, the suffering of a continuous cold, a lot of mucus and numerous ear and nose inflammations. Surprisingly enough, half of the patients who suffer from this syndrome have their organs placed in mirror image positions, the heart being at the right instead of the left side of the chest, a condition known as situs inversus. There is currently no cure available and treatment mainly focuses on the upper and lower respiratory tracts complications. None of the genes responsible have been identified, although the complex architecture of celia suggests genetic heterogeneity. The current, European funded project has performed a genome-wide linkage analysis. Samples from 61 European and North American families with PCD were collected. The genome-wide linkage search was performed in 31 multiplex families; 169 individuals, 70 of those affected; using 188 evenly spaced polymorphic markers. No major locus was detected; in contrast the results strongly suggested extensive locus heterogeneity. It seems, from the results analysis, that this very heterogeneous autosomal recessive phenotype of PCD has at least 3 most likely genes responsible for this phenotype in different families. The motility of cilia is due to dynein complexes that are mainly composed of axonemal dynein heavy chains. 9 of the genes of the chains were identified, one of which had never been identified before. The results obtained can provide the basis for future research into a causative treatment of the disease using, phenotype-genotype correlations, PCD genes characterization and an understanding of its pathophysiology. Given the rarity of cases of PCD in conjunction with its complexity, future multinational collaborations are necessary, with the involvement of scientists and experts in complimentary fields, to identify the responsible genes and ultimately produce a cure.
