The various autosomal recessive diseases cause a wide variety of clinical pictures with a wide variety of prognoses. Some are not compatible with normal embryonic development (survival) and result in the death of the foetus already during pregnancy (miscarriage). Other diseases can lead to severe congenital, mental or physical disability. In some cases, life expectancy and quality of life are practically unaffected if therapeutic measures are taken in time; for other diseases, there are no treatment options. In certain circumstances, the risk of developing a disease may be detected at a later stage of life, which does not affect life expectancy, but for which there are nevertheless no or very limited treatment options. Consequently, the considerations and consequences for couples in case of an abnormal test result vary.