The Hardy Weinberg law is used in population genetics and dates back to 1908 and 1909, when it was discovered independently by the English mathematician Geoffrey Hardy and the German physician Wilhelm Weinberg, respectively. The Hardy Weinberg law makes it possible to determine the frequency of different genotypes in a diploid chromosomal complement (i.e., where two separate copies of a certain gene exist). In clinical genetics, it is mainly used for determining the frequency of heterozygosity in autosomal recessive heritable disorders when only the disease frequency in known.