Our understanding of hereditary diseases has taken huge strides forward since the code of the human genome was cracked at the start of the century. For example, about 20 gene defects have been linked to primary ciliary dyskinesia (PCD), a disorder causing missing or malformed cilia – the microscopic hair-like structures that help keep the inner surfaces of our airways and sinuses free from infection. The latest to be identified is in a gene called LRRC6, which results in cilia lacking dynein, a protein essential to their sweeping motion. In the highly magnified cross-sections of cilia pictured, arrows show the position of dynein structures in a cilium from the airway of a normal person (top left) and normal lung (bottom left). In the airways of a PCD sufferer (top right) and in lung cells given the LRRC6 defect (bottom right), arrows mark their absence. Without dynein ‘broom handles’ cilia can’t sweep.
Written by Mick Warwicker
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