Early Conjectures That Down Syndrome Is Caused by Chromosomal Nondisjunction

Abstract

In 1959, cytologic studies demonstrated that Down syndrome was associated with a nondisjunction now known as trisomy 21. Twenty years earlier (1932-39), at least three writers conjectured, independently of one another, that Down syndrome might be a form of nondisjunction: Petrus J. Waardenburg (1932), Adrien Bleyer (1934), and G. Fanconi (1938). In separate papers, Raymond Turpin (1937), Walter E. Southwick (1939), and Lionel S. Penrose (1939) also proposed that Down syndrome could be a chromosomal anomaly, but without specifying nondisjunction. However, these conjectures were largely ignored by contemporary medical writers. This essay (1) explores the background and context of early conjectures that Down syndrome is a form of nondisjunction, (2) provides some possible reasons why these conjectures were not given greater credence, and (3) traces early efforts to assimilate Down syndrome and other genetic disorders to what Robert Koch called the etiologic standpoint.

In Defence of Reason: Religion, Science, and the Prince Edward Island Anti-Abortion Movement, 1969–1988

“…24 One of the loudest scientific voices in the transnational pro-life movement was Jerome Lejeune, the French geneticist who discovered the connection between chromosome abnormalities and intellectual disabilities in the 1950s. 25 Lejeune, outraged that the medical community used his research to justify the termination of fetuses, became a prominent pro-life advocate and his research appeared often in the RTLA's newsletters and briefs presented to medical professionals. 26 New Zealand gynaecologist and obstetrician A.W.…”