Genetic aspect of mood disorders

ABSTRACT

The diagnosis included 9 cases bipolar depression, 9 cases unipolar and 2 cases dysthymic disorder. Positive blood consanguinity reported in 56% of unipolar cases compared to 67% of bipolar. Recurrence risk for relatives of the prob and s studied was 20% in unipolar depression, equal in a 1st and 2nd degree relatives compared with 17.3% in bipolar cases, this was higher in 2nd degree relatives [25%] than 1st degree relatives [9.1%] and reached 17% in dysthymic cases. This was generally correlated to the severity of illness of disorder of prob and s. Pattern of inheritance according to pedigree studies was concordant with different modes of inheritance in the following frequency, autosmal dominance 35% polygenic 20% autosomal dominance with reduced penetrance 15% and 15% for both autosomal recessive and X linked pattern. Genetic statistical analysis confirmed the polygenic inheritance in both unipolar depression and suggests a major environmental component in dysthymic disorder. This study permits a new no-sological approach as well as major role for genetic counseling in affective disorder