Trisomy 21 originated with Homo sapiens, or even before, as it exists in other primates. However, in antiquity, Down’s syndrome was rare: mothers were younger, and children failed to reach adulthood. For centuries, trisomy 21 and hypothyreosis were confused. Scientific reports originated from asylums for the mentally retarded. In 1866, John Langdon Down at Earlswood published a description of symptoms in his ‘Ethnic classification of idiots’ and coined the term ‘Mongolian’. Jerôme Lejeune identified an additional chromosome 21 causing the disorder. Maternal age rose markedly for various reasons, as did the prevalence of trisomy 21. From 1968, high-risk pregnancies were screened and interrupted because of Down’s syndrome. Non-invasive techniques now enable all pregnancies to be screened to detect chromosomal anomalies early and precisely. The topic is hotly debated and consensus unlikely. Legislation will not halt scientific progress, but it should ensure that in the same society contradictory attitudes can be held and mutually respected: the right to accept a disabled infant and the right not to accept it.
Characterization of monomeric and soluble aggregated Aβ in Down’s syndrome and Alzheimer’s disease brains