[Multiple chromosome aberrations in 3 generations of a family and Down's syndrome resulting from partial trisomy of chromosome 21 (q21--q22)].

Two balanced translocations (1; 16) (q22; q11) and t(21; 22) (q21; p11), partial inversion of chromosome 9 and variant 16gh + were detected in the family of the child with Down's syndrome. The proband clinical picture was due to trisomy of the distal region of the long arm of chromosome 21 (q21----q22). Proband's karyotype was 46, XY, --22, +der(22), t(21; 22)mat, inv(9). Carriers of variant 16gh+ had a normal phenotype and a normal reproductive function. The relation is discussed of the balanced translocations and C-heterochromatin to the development of following chromosomal aberrations. A probability prediction of the progeny is given. It is advisable to make a prenatal diagnosis of the fetal chromosome set for each subsequent pregnancy.