Occurrence of sex chromosome mosaicism and translocation Down's syndrome in the same family.

The proband in this family has translocation Down's Syndrome 46,XX,t(14;21)(p11;q11), and this translocation was present in other family members. Sex chromosome mosaicism was demonstrated in three generations of the family, providing another example of familial mosaicism. There was also excessive foetal wastage in different family members. It was not possible to assign the common aetiological factor to account for these various abnormalities. Dermatoglyphic studies showed dominant inheritance of finger-tip arch patterns in one branch of the family.