[Trisomy 12(pter----q12) and monosomy 21(pter----q21). A propos of a case].

: The authors report an observation of a child with both trisomy 12(pter----q12) and monosomy 21(pter----q21). It is thus possible to detect the clinical signs which can be attributed to trisomy 12p and to monosomy 21ql respectively. The authors point out the originality of the maternal translocation which differs from the translocations affecting these two chromosomes previously described in the literature. Finally, the rarity of the type of adjacent-2 segregation is shown, and discussed according to the literature already published.