Rahu in Lagna or Ascendant

The person has strong foreign elements within himself. He will be "different" from his family's thinking, his family's tradition. 

His personal philosophy will be distant, and his social mix will be awkward. He is in a local body (relative to his community), but his mind and spirit is like that of a different culture. 

Inadvertently, most people with Rahu/1 will end up mixing with people not of his own race, or even marrying spouses out of their own race. Take a look at their best friends; they'll be of different races than himself.