Investigation of a cluster of children with Down's syndrome born to mothers who had attended a school in Dundalk, Ireland

Abstract

Objectives-To investigate a reported cluster of Down's syndrome in oVspring of former pupils of a girls' school in Ireland, to establish the prevalence of Down's syndrome among live births in the area around the school, and to review the literature on the possible causes of reported clusters of Down's syndrome. ), although only four of these mothers were attending the school at any one time. The origin of the non-disjunction was found to be maternal first meiotic in four children, mitotic after fertilisation in another (with the youngest mother), and in the remaining one could not be determined. The marked excess of Down's syndrome in births to young mothers did not extend to oVspring of former pupils of the other Dundalk girls' school surveyed, or to live births in County Louth generally or in adjacent Newry and Mourne District. Conclusion-A striking, highly localised, excess of Down's syndrome in births to young mothers who had attended a girls' school in Dundalk during 1956-57 has been confirmed. However, not all of the mothers of the aVected children attended the school concurrently and the origin of non-disjunction in one child was an error occurring after conception. Some exposure essentially confined to girls attending the school at this time is a possible, although unlikely, explanation, but a review of potential risk factors does not suggest what this could be. Previous suggestions that an influenza epidemic or contamination from the Windscale nuclear reactor fire might be implicated, both of which occurred in October 1957, can be eVectively dismissed because three of the women with aVected oVspring had left the school by then and had moved away from Dundalk, and Down's syndrome in the child of another mother originated in an error after fertilisation. Owing to the retrospective nature of the investigation and the characteristics of the cases, chance is the most likely explanation for the cluster.

Genetics of Down Syndrome

“…The atomic bomb blasts in Japan at the end of the World War Two and the explosion of the atomic reactor in Chernobyl in 1986 are well-known examples of exposures and have been thoroughly explored. However, they did not lead to an increased birth of children with DS (Dean et al, 2000). Furthermore, neither contact with different organic substances or heavy metals nor an increased consumption of caffeine, alcohol, or nicotine could be shown to increase the number of births of children with trisomy 21 or other chromosome aberrations.…”

Genotoxic Effects in Human Fibroblasts Exposed to Microwave Radiation

“…In summary, nuclear weapons test participants received the highest radiation doses of any population from nuclear test Studies of environmentally exposed populations and transgenerational effects. Transgenerational studies have been conducted in areas of high natural background radiation in India (Jaikrishan et al 1999) and China (Wei et al 1990) and in areas in Ireland exposed to airborne releases from a nuclear fuel reprocessing plant (Dean et al 2000). The radiation sources in the environment include thoriumcontaining monazite sands and effluents from nuclear facilities (NCRP 2013).…”

“…An increased rate of Down syndrome among residents in areas of high background radiation in China was later attributed to increased maternal age at birth and to better case ascertainment in the high background radiation areas compared with the control areas (UNSCEAR 1993;Wei et al 1990). Airborne radiation released from the Sellafield nuclear fuel reprocessing plant in England was claimed to have caused a cluster of Down syndrome on the coast of Ireland but was later discounted (Dean et al 2000). Studies of 140,000 inhabitants residing in Kerala, India, in areas of high natural background radiation (15 to 25 mGy annual whole-body dose) reported increased rates of Down syndrome (Kochupillai et al 1976), which were not confirmed in subsequent studies that used more reliable sources of information (Kesavan 1997).…”

Retrospective Search for Evidence of the 1957 Windscale Fire in NE Ireland Using 129I and Other Long-Lived Nuclides

“…Contamination measurements were also made on a daily basis at two Irish sites, namely, Dublin and Valentia. However, the incident did not receive a great deal of public attention in Ireland until almost thirty years later, with the tentative suggestion that there was a link between a cluster of Down's syndrome cases in Dundalk (a town situated on the northeast coast of Ireland) and the Windscale accident ( − ).…”