In the much awaited Myriad decision (Association for Molecular Pathology v Myriad Genetics Inc 12-398) on the patentability of gene sequences, the US Supreme Court unanimously held that a naturally occurring DNA segment is a 'product of nature' and is not patentable subject matter merely because it has been isolated. However, it was held that cDNA is patentable subject matter because it is not naturally occurring.

It is important to note that the patents at issue did not involve new applications of knowledge about BRCA1 and BRCA2 gene. Further, the court did not consider the patentability of DNA in which the order of naturally occurring nucleotides had been altered. In addition, no method claims were before this court.

Some commentators suggest that the impact of the US Supreme Court's decision on biotechnology business interests in the USA is likely to be less restrictive than forecasted by the headlines in some of the press.

This development in the USA should have no effect on the current situation in Europe, where gene sequences isolated from their natural environment can be patented (Directive 98/44/EC) if the sequences fulfill the requirements of patentability (novelty, inventive step, industrial applicability, etc). Under European patent practice, the function of the gene must be known and disclosed in the specification order to meet with industrial applicability requirements. It is interesting to note that, in Europe, a claim directed to a DNA sequence may only cover that sequence when it is 'performing' its stated function (CJEU Monsanto Technology LLC v Cefetra BV and others).