Natural history of molecular pathology

: The author recalls the main stages of biosynthesis of proteins based on molecular pathology : transcription of DNA into messenger RNA, the genetic code, translation of protein molecules and regulation of their synthesis. Examples are then given of qualitative and quantitative disturbances. Qualitative disturbances with synthesis of abnormal proteins, or protein diseases of protein structure, together with their consequences. Quantitative disorders, with modified synthesis of normal proteins, result very often from abnormalities of structural genes, but also from abnormalities of transcription or translation. The author considers, in conclusion, pathological situations based on molecular abnormalities for mutations occur at random and it may be possible to correct them by genetic manipulation.