format
Matrix with columns:
rlll{
[,1] affected numeric affection status (1=yes, 0=no)
[,2] gender numeric coded as 0 for female and 1 for male
[,3] age numeric in years
[,4] BMI numeric Body Mass Index
[,5] M90.1 numeric the first allele of hypothetical SNP M90
[,6] M90.2 numeric the second allele of hypothetical SNP M90
[,7] M91.1 numeric the first allele of hypothetical SNP M91
[,8] M91.2 numeric the second allele of hypotetical SNP M91 }