If several traits are measured for the same locus, the phenotype is the list of all the variables. A single value of 0.0 in the list is interpreted as an unknown phenotype. The means must be given for each variable as a function of genotype, along with the variance-covariance matrix. The variance matrices for homozygotes and heterozygotes can differ by a constant factor.
For sex-linked traits it is assumed that males will have an affection-status variable rather than a quantitative value. If several variables have been measured (ntrait), a male phenotype consists of affection status followed by ntrait-1 arbitrary entries (for example, zeros). The present version of the programs supports only one affection status class, with full penetrance of the disease allele for sex-linked traits.