A computerized database generated from the literature on cytogenetic studies in couples experiencing repeated pregnancy losses has been set up at the University of Quebec at Chicoutimi. At the present time, it contains data on 22,199 couples (44,398 individuals). The statistical analyses showed a relationship between the distribution of the chromosome abnormalities and the number of abortions. An uneven distribution of the chromosomal structural rearrangements according to the sex of the carrier was found (P less than 0.05). Overall, 4.7% of the couples ascertained for two or more spontaneous abortions included one carrier. It also appeared that only translocations (both reciprocal and Robertsonian) and inversions were associated with a higher risk of pregnancy wastage. Therefore, genetic counselling should be offered to these couples and investigations performed on their extended families.
Myotonic dystrophy (MD) is an autosomal dominant disorder that has a high prevalence in Saguenay‐Lac‐St‐Jean. A case‐control study, based on a population register, of 373 MD patients who married in this region between 1855 and 1971 was conducted to determine whether their fertility was affected by the disorder. Six demographic parameters, that is the number of children, the age at marriage, the ages at the time of birth of the first and the last child, the interval between the marriage and the birth of the first child, and the interval between consecutive births, were analyzed. The mean number of children born to MD and control individuals was not different (P>0.05). However, MD males had more children than MD females although they have started delaying their marriage since 1921. Fertility fell significantly in both the MD and control groups during the period of observation. This change reflects the decline in fertility of French Canadians in general during this period, but mainly after 1940.
Infant mortality among children born to 373 individuals with myotonic dystrophy (MD) who lived in Saguenay-Lac-St-Jean during the period 1838 to the present time was analyzed using a case-control approach based on a population register. A statistically significant increase was found in the rate of deaths during the first week of life among children born to MD mothers (57.5%) compared to control mothers (34.8%) and MD fathers (39.1%) (p < 0.01). The stillbirth rate was not increased. The rate of mortality after the first week fell significantly in both MD and control groups during the period of observation. There was evidence of a slight selective disadvantage among this MD population.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.