GATT is an agreement under the WTO that states controls which patent laws a country can adopt.  WIPO is not only a treaty but a patent filing, search and preliminary examination system.  Many small countries rely on the WIPO examination and, so, have to do less examination themselves.

The World Intellectual Property Organization (WIPO) is the global forum for intellectual property services, policy, information and cooperation (http://www.wipo.int/portal/en/index.html).

The intellectual property services provided by WIPO include treaty-based services such as:  Patent Cooperation Treaty (PCT) (International patent application processing service), Madrid System and Protocol (International trademarks application processing), Hague System (designs), and Alternative Dispute Resolution (ADR) (dispute resolution). 

Whereas GENERAL AGREEMENT ON TARIFFS AND TRADE (GATT) is an international treaty and an organization, which became the World Trade Organization in 1995 through the General Agreement on Tariffs and Trade 1994 (GATT 1994), at Marrakesh, which is distinct from the GATT 1947, Geneva . GATT went out of existence with the formal conclusion of the Uruguay Round on April 15, 1994, and its principles and the many trade agreements reached under its auspices were adopted by the WTO.

The WTO (previously the GATT) is the force behind the Globalization that helped to create a strong and prosperous international trading system - the global economy - thereby contributing to unprecedented global economic growth. The WTO currently has 164 members and continue the practice of decision-making by consensus followed under GATT 1947.

Prime Minister Thatcher, President Reagan, and their successors tore down barriers to trade using the power of money through IMF and the World Bank, and through mechanisms like the General Agreement on Tariffs and Trade (GATT, substantially reinforced from 1986-1993), the North American Free Trade Agreement (NAFTA), the formation of the European Union, and ultimately the WTO (previously  the GATT). All these agreements and organizations were developed to promote free trade. In fact, upon the signing of the first GATT agreement, the US along with 22 other countries agreed to effectively lift 45,000 tariffs that existed.

Now, the globalization has reached a stage, where the kinetic and potential energies are so powerful, nobody can stop it - like the Supreme Juggernaut (Jagannadh)- neither BREXIT nor TRUMP. Now, the fate of humanity will be decisively decided by a multipolar world and economy. 

Developed countries dominated the debate and construction of TRIPS (GATT), they did not dominate the discussion at WIPO - the US lost patience and forced IP reform into GATT where the developing countries had more pressing issues on their minds than IP (eg market access) and as a result the agenda of the developed countries prevailed in the adoption of a one-size-fits-all schema under TRIPS. See Sell, Drahos, Matthews etc on the TRIPS negotiations

One of the major debates at the GATT Uruguay Round was about the TRIPS provision and here the issue of product patents and/or process patent. The latter protected the process of creating a particular product (e.g. pharmaceutical drug), but not the product itself allowing the production of generica. Another aspect was whether life forms can be protected by patents, e.g. hybrid seeds or genetically modified seeds in agriculture, or the human genome. Like mentioned developing countries had more influence under WIPO as in GATT developed countries traded in aspects of trade liberalization in agriculture and textiles (developing countries wanted this to happen) against TRIPS, TRIMs (trade related investment measures) and services.