Portrait of autosomal recessive diseases in the French-Canadian founder population of Saguenay-Lac-Saint-Jean.

The population of the Saguenay-Lac-Saint-Jean (SLSJ) region, located in the province of Quebec, Canada, is recognized as a founder population, where some rare autosomal recessive diseases show a high prevalence. Through the clinical and molecular study of 82 affected individuals from 60 families, this study outlines 12 diseases identified as recurrent in SLSJ. Their carrier frequency was estimated with the contribution of 1059 healthy individuals, increasing the number of autosomal recessive diseases with known carrier frequency in this region from 14 to 25.

Experience of carrier couples identified through a population-based carrier screening pilot program for four founder autosomal recessive diseases in Saguenay-Lac-Saint-Jean.

Unlabelled: A pilot population-based carrier screening program started in 2010 in the Saguenay-Lac-Saint-Jean region of Quebec, Canada, for four recessive diseases with local founder effects (tyrosinemia type I, autosomal recessive spastic ataxia of Charlevoix-Saguenay, congenital lactic acidosis, and Andermann syndrome).

Objectives: The objective of this study was to describe the experience of carrier couples identified through this program.

Methods: Semi-structured interviews were performed with carrier couples.

Anticipation in myotonic dystrophy type 1 parents with small CTG expansions.

Myotonic dystrophy type 1 is the most common form of adult muscular dystrophy and has the world's highest prevalence in the Saguenay-Lac-St-Jean region, due to a founder effect. This autosomal dominant disorder results from an unstable CTG repeat expansion in DMPK. This region of Canada has had a family screening and predictive testing program for this disorder since 1988.

Factors associated with an individual's decision to withdraw from genetic testing for breast and ovarian cancer susceptibility: implications for counseling.

Our study aimed to examine why individuals withdraw from genetic testing for breast and ovarian cancer susceptibility. We explored the characteristics of 334 individuals from high-risk breast and ovarian cancer families who declined genetic testing for BRCA1/2 mutations, when, and why they did so. Individuals who declined genetic testing were older, and a greater proportion had never developed breast or ovarian cancer.