survival and redox activity of friedmanniomyces endolithicus an antarctic endemic black meristematic fungus after gamma rays exposure despite living organisms are not exposed to acute ionizing radiation under natural conditions some exhibit a high radiation resistance understanding this phenomenon is important for assessing the impact of radiationrelated accidents occupational exposures and space missions in this context in this study we analyzed the effect of gamma rays on the antarctic cryptoendolithic melanized fungus friedmanniomyces endolithicus ccfee 5208 and demonstrated its resistance to acute doses of gamma radiation up to 400 gy accompanied by increase in metabolic activity cloustons ectodermal dysplasia a case report with biochemical study of keratin one familial case of ectodermal dysplasia of the cloustons type is reported the clinical picture consisted of hypotrichosis and dysonychia with normal sweating the disease follows dominant autosomal transmission histologically keratin was slightly abnormal the biochemical study of keratin of hair and nails showed diminished cysteine