Mitochondria are energy making organelles within our cells. Iron-sulphur cluster assemblies (Fe-Sc) take part in the energy production within mitochondria. Problems during the Fe-Sc assembly or reduction in the amount of the assembly molecules may be damaging to brain cells such as myelin sheaths. Such damage may eventually cause degeneration in white matter in human brain and leads to neurodegenerative diseases. We investigated six patients with leukodytrophy from five unrelated families and discovered first disease-causing mutation in ISCA2, an essential molecule for maturation of mitochondrial Fe-Sc. The mutation seems an ancient one that was likely appeared around 4800 years ago. (By Dr. Namik Kaya, http://jmg.bmj.com/content/early/2014/12/24/jmedgenet-2014-102592 )