Genetic counseling of teenagers is challenging and complex. The ability to think abstractly, a sense of self and independence from family all develop during adolescence. Predictive genetic testing counseling protocols presuppose that these qualities exist, requiring the at-risk individual to consider the short and long term consequences of testing as well as their motivations. Eighteen year olds are in transition from adolescence to adulthood; eligible for predictive genetic testing, they may not yet be independent of their family or able to articulate their feelings. This paper presents case studies from the authors' clinical practice to illustrate some of the difficulties faced by genetic counselors when 18 year olds request predictive testing for Hereditary Non-Polyposis Colorectal Cancer. By reflecting upon their experiences with these young adults and their families, the authors' intention is to generate discussion about genetic counseling strategies, particularly for predictive genetic testing, that are both age-appropriate and family-sensitive.