Mawu a M'munsi

a M’chingelezi matendawa amatchedwa kuti Down Syndrome chifukwa chakuti munthu woyamba kulemba nkhani yolondola kwambiri yokhudza matendawa, anali John Langdon Down. Munthuyu anali dokotala wa ku England ndipo analemba za matendawa m’chaka cha 1866. M’chaka cha 1959, wasayansi wina wa ku France, dzina lake Jérôme Lejeune, anatulukira kuti ana odwala matendawa amakhala ndi ma chromosome 47 m’malo mwa 46. Kenako ofufuza anapeza kuti chromosome yowonjezerayo inali yofanana ndendende ndi chromosome nambala 21.