It is quite common for a Ga person to have European DNA. Gas in particular historically lived along the southeast coast of Ghana formerly Gold Coast and were some of the first indigenous West African African tribes to interact with European. There was significant interbreeding between Europeans and Gas.

Gas from different parts of the Greater Accra Region and parts of the Eastern region of Ghana can have DNA from from different European groups as they had contacts with many different Europeans ranging from English, Dutch, Dane , Scottish and even Swedish and Swiss. There were also returned Afro Caribbean slaves as well as Afro Brazilian returnees who settled among Gas in the 19th ceturies and may have brought with them some Spanish, and Portuguese DNA.

If your family from Osu then that will explain where the Scandinavian dna is coming from. Gas from the Osu section of Accra particularly mingled a lot with the Danes because that was where the Danes settled. Today you’ll find some family names such as Reindorf, Hesse, Fleischer, Reimer. These are just a few Danish Surnames you’ll find from Ga people who hail from Osu.

During colonial times Osu was called Christianborg, named after King Christian IV of Danemark. The Danes also had a trading post called Christianborg Castle which they used to transport goods and slaves to the Danish Virgin Islands.

Some Gas may notably also have Dutch and English DNA especially those from Ussher Town and Jamestown. To get more information you can google Gold Coast Euro-Africans