--These results suggest the A1 allele of the DRD2 gene is associated with a number of behavior disorders in which it may act as a modifying gene rather than as the primary etiological agent.

No abstract

We review evidence suggesting that many individuals with Tourette syndrome (TS) may be homozygous for a "Tourette syndrome" gene. This is based on experience with pedigrees on 1,200 TS families, comparison of the occurrence of tics or associated behaviors such as obsessive-compulsive behavior, panic attacks, attention deficit hyperactivity disorder, and/or severe alcohol or drug abuse, on both the maternal and paternal side in 170 TS families compared to control families, biochemical studies of blood serotonin and tryptophan levels, and other evidence. These observations suggest the inheritance in TS may be best described as semi-dominant, semi-recessive. Some of the implications of this proposal are discussed.

No abstract

Complexities abound in the identification and management of families at increased risk for inherited forms of cancer. One of the ways to learn as a profession how best to provide cancer risk counseling (CRC) is to share counseling experiences. Such cases can provide insight into the issues raised by families and ways in which genetic counselors have handled complex situations. Here we describe three CRC cases initially presented at the 1995 American College of Medical Genetics meeting. The first case involves balancing the importance of informing a family of the presence of an inherited cancer syndrome with the family's right "not to know." The second case illustrates the difficulties in assisting an individual to make medical management decisions in the face of uncertain risk information. The third case describes the complex interactions with a woman before and after her decision to have prophylactic surgery.