George R.R. Martin describe one of his most popular and strong character of his saga Game of Thrones, Daenerys Targaryen as a young female with purple almond eyes, pale skin and silver white hair. She is heir of one the most important dynasties, the house Targaryen. All Targaryen members have this characteristics.
But, what is special in this description? It sounds like the albinism phenotype. The albinism is a genetic disease characterized for a lack of pigmentation (melanin) in eyes, skin and hair. It is common in both human and animals. Also appears in vegetables, but what is it missed is carotenoids pigments. Its origins is a mutation on 11th chromosome and it is heredity from both parents.
It is a recessive gen, so the parents could have one copy of the gene (allele) and have a normal phenotype. A non affected person, the cells called melanocytes, transform the amino acid tyrosine into melanin through the activity of an enzyme called tyrosinase. Exist different types and grades of albinism.
Consanguinity is one cause of albinism. And who marry with relatives? The Targaryen house.
So, drawn your own conclusions. Are Targaryen albinism?