I am not offering this article as medical advice! After all, there is increased risk of children suffering genetic defects like extra fingers and toes. However, if you are seriously thinking about marrying your first cousin, you really need to first check an article by Cassidy Morrison published in the DailyMail web site.

And, oh yes... also check with a lawyer.

According to the article:

"Studies show that children born of two blood-related parents have double the risk of congenital problems such as heart and lung defects, cleft palettes, and extra fingers.

"Children of inbreeding are also twice as likely to be treated for an illness requiring antipsychotic medicines, like schizophrenia.  

"Yet despite the known risks of inbreeding in humans, 19 US states and the District of Columbia still allow marriages between first cousins. They mostly fall on the coasts and in the southern states."

You can learn a lot more at: https://www.dailymail.co.uk/health/article-11934633/The-19-states-marry-cousin-despite-inbreeding-risks.html.

Of course, numerous people have married their first cousins in the past:

Queen Victoria married her first cousin, Prince Albert of Saxe-Coburg and Gotha, in 1840.

In 1919, famed physicist Albert Einstein married Elsa Lowenthal, who was his first cousin on his mother's side as well as his second cousin on his father's side.

Jerry Lee Lewis married his first cousin, Myra Gale, when she was 13 and he was 22 years old.

At age 27, American poet Edgar Allan Poe married his first cousin, Virginia Eliza Clemm, while she was just 13 years old.

Composer Johann Sebastian Bach married his first cousin, Maria Barbara, in 1701. She was a vocalist, and together, they had seven children.