Genetic counseling in a navajo hereditary nonpolyposis colorectal cancer kindred

BACKGROUND. Cross-cultural genetic counseling was provided to an extended Navajo Indian family in which the MLH1 gene mutation for hereditary nonpolyposis colorectal cancer (HNPCC) had been identified. The family Ifad been observed try the authors since 1983 and over tire years had been provided with intensive education regarding tire natural history of HNPCC as well as recommendations for cancer surveillance and management that was responsive to this natural history. METHODS. Following identification of the MLH1 mutation, DNA from family members was evaluated by a reference laboratory (OncorMed, Gaithersburg, MD), where sequences were checked in both the forward and reverse directions against the published sequence for MLH1. The 4bp deletion beginning at the first nucleotide of codon 727 was easily visualized in the heterozygous condition in both affected anti predispositional individuals. The family was reeducated as it group and then provided further education individually during genetic counseling sessions, at which time they were appraised of potential penalties, such as insurance and employer discrimination, and psychological sequelae that could result from knowledge of the MLH mutation. Strict confidentiality of this information was assured. RESULTS. DNA testing was performed on 51 family members. Twenty-three individuals were counseled, seven of whom were positive for MLH1. Reactions ranged from full acceptance of the genetic implications to traditional Navajo reasoning such as the family had been cursed. CONCLUSIONS. DNA based genetic counseling requires compassion and empathy, coupled with intensive preeducation regarding potential penalties and advantages that might emanate from this knowledge. Special care must be given to patients' culture, beliefs, and traditions.