Pedigree of the Friesian cattle family used in this study. Pedigree includes the genotypes at the mutation site of EDA gene. Animals affected with anhidrotic ectodermal dysplasia are shown as solid symbols. Affected calves (A1, A2) were hemizygous A/-, the mother (M) and four sisters (S1, S2, S3, S4) were heterozygous G/A, the healthy brother (Hb) was hemizygous G/-. The pedigree is consistent with an X-chromosomal, recessive trait.