AUTOSOMAL RECESSIVE DISORDERS IN SAGUENAY-LAC-SAINT-JEAN (QUEBEC, CANADA) - ESTIMATION OF INBREEDING FROM ISONYMY

The total inbreeding coefficient of a group of 574 individuals with au tosomal recessive disorders (ARD) from Saguenay-Lac-Saint-Jean, a geog raphically isolated region of northeastern Quebec, was estimated from isonymy and compared to the mean inbreeding coefficient calculated fro m the genealogies. Its value was compared to that of 1722 matched cont rols. The total inbreeding coefficient was similar in both ARD and con trol groups, but higher than the values calculated from the genealogie s. Most of the increase was due to the random component of inbreeding. This isonymy study confirmed that the high frequency of ARD in Saguen ay-Lac-Saint-Jean is mainly the result of founder effect and genetic d rift.