The academic basis of Mandel’s inheritance patterns, chromosomes, molecular biology science and technology were the basis to decipher causes and types of genetic mutations, prospectives of the international gene project as well as gene mapping. The clinical aspect of the study included definition of genetic hearing loss, prevalence and the clinical presentation in all ages with special details of the commonest classifications. Combined clinical biology and biomolecular technology aspects in identifying genes with special details about connexin 26 expression and functions were detailed. The last chapter included clinical and laboratory diagnosis and Future insight in gene therapy.