A dominantly inherited syndrome (microcephaly, short stature, peculiar facies, mental retardation) associated with two balanced rearrangements involving chromosomes 2;7 and 5;20.

A complex balanced three-break-point rearrangement between chromosome 2 and chromosome 7 and a balanced reciprocal translocation between chromosome 5 and chromosome 20, were found associated in a girl and in her mother and grandmother. All three of them have microcephaly, low stature, peculiar asymmetric facies and slight mental retardation. We postulate that one (or more) of the five chromosome break-points disrupted one (or more) gene, leading to the expression of the syndrome and to its segregation with the chromosome rearrangement in three generation. Our finding confirms the efficiency of balanced translocations for gene mapping, althought it has led only to the exclusion mapping of all chromosomes except 2, 5, 7 and 20.