Clustering of Trisomy 18 in Kuwait: Genetic Predisposition or Environmental?

Abstract

Background: This study describes 59 newborns with regular trisomy 18 (Edwards' syndrome, T18) who were ascertained clinically and cytogenetically at the Kuwait Medical Genetic Centre from 1994 to 1997, out of 118 T18 cases identified from 1980 to 1997. Materials and Methods: T18 cases were ascertained clinically and cytogenetically shortly after birth. In addition to assessing the T18 birth prevalence rate and confidence limits during the years 1994-1997, we investigated the possible etiological factors by a case-control study with normal healthy newborns. Studied factors included gender, parental age, birth order, abortion, clinical variables (presentation, amniotic fluid and mode of delivery), and survival. Results: The average T18 birth prevalence rate during the period was 8.95 per 10,000 live births (95% confidence limits 6.66-11.23). The T18 cases were mostly females, with a male:female ratio of 1:2.1, and the majority (53%) died before the second week of life. Maternal age above 30 years was found to be a significant factor for T18. Conclusion: This high T18 birth prevalence rate suggests clustering of T18 in the highly inbred population of Kuwait. Such clustering may indicate a possible environmental, and to a lesser extent, genetic predisposition to aneuploidy nondisjunction.

The effects of advanced paternal age on fertility

“…1,69 APA has not been found to be associated with trisomy 18. 70,71 Fathers of APA were less likely to sire offspring with trisomy 13 and no relationship has been shown between APA and the birth of an offspring with anencephaly or encephalocele. 69 With regard to Klinefelter syndrome, the population risk is around 1 in 500, 72 and one study found this to be increased to 1 in 312 in men of APA .50 years old.…”

Therapeutic Management and Outcomes of Hepatoblastoma in a Pediatric Patient with Mosaic Edwards Syndrome

“…The incidence of Edwards syndrome may be influenced by factors such as the mother's advanced age, environmental factors, and low socioeconomic level [13,14]. In this case, both advanced maternal age and low socioeconomic status were noted.…”

Trisomy 18: A difficult decision for the family

“…Several studies in the literature have reported that advanced maternal age, environmental pollution, and low socioeconomic status have an effect on this occurrence. Although advanced maternal age has been reported in multiple studies, trisomy 18 has also been described in young mothers, including those at the age of 20 [8][9][10]. It is twice more common in female babies [2,[4][5][6][7].…”