Risks pertaining to actual genetic testing are very limited. The physical process of drawing out a blood sample or taking a buccal smear does not pose any risk by itself. However, in DNA sampling using amniocentesis or chorionic villus sampling, where a portion of the amniotic fluid needs to be extracted from the sac, great care has to be taken so that it does not cause a miscarriage.
Moreover, genetic tests may create a kind of stress and fear related to the results. A positive result might create a friction within the family and the person may feel socially isolated. Genetic testing can be expensive and may become a financial burden.