Concordant deuteranomaly in monozygotic twin sisters (author's transl)]

Colorblind twin sisters were born from the marriage of a hemizygote with a carrier for colorblindness. The proof of monozygosity is given by the blood-group typing and the dermatoglyphs. The deuteranomaly is of the same degree in each but is more marked in one of the sisters. The mother has none of the microsymptoms sometimes found in carriers.