GENETICS AND HEALTH ASSESSMENT
Assessment of a person’s genetics-related health status is an on-going process. The nurse collects information that can help identify individuals and families who have actual or potential genetics-related health concerns or who may benefit from further genetics information, counseling, testing, and treatment. This process can begin before conception and continue throughout the lifespan. Nurses evaluate family and past medical histories, in-cluding prenatal history, childhood illnesses, developmental his-tory, adult-onset conditions (if adult), past surgeries, treatments, and medications; this information may relate to the genetic con-dition at hand or being considered. The nurse also identifies the patient’s ethnic background and conducts a physical assess-ment to gather pertinent genetics information. The assessment also includes the patient’s culture, spiritual beliefs, and ancestry. Genetics-related health assessment always includes determining a patient’s or family’s understanding of actual or potential health concerns related to genetics and understanding how these issues are communicated within a family (ISONG, 1998; Lea, Jenkins & Francomano, 1998).
Nurses in any practice setting continuously assess genetic family history to identify the presence of a genetic trait, inherited con-dition, or predisposition. A questionnaire (Chart 9-3) is often used to identify genetic conditions for which further information, ed-ucation, testing, or treatment can be offered. In consultation and collaboration with other health care providers and specialists, the nurse can then determine whether further genetic testing and evaluation should be offered for the trait or condition in question. A detailed and accurate family history provides the most com-plete genetics health information. The family history should in-clude at least three generations, as well as information about the current and past health status of all family members, including the age of onset of any illnesses and cause of death and age at death. The nurse also inquires about medical conditions known to have a heritable component and for which genetic testing may be of-fered. The nurse obtains information about the presence of birth defects, mental retardation, familial traits, or similarly affected fam-ily members (Lashley, 1998; Lea, Jenkins & Francomano, 1998).
The nurse also considers the presence of genetic relatedness (consanguinity) among family members when assessing the risk for genetic conditions in couples or families. For example, when obtaining a preconception or prenatal family history, the nurse asks whether the prospective parents have common ancestors (ie, they are first cousins). This is important to know because indi-viduals who share ancestors have more genes in common than those who are unrelated, thus increasing their chance for having children with an autosomal recessive inherited condition such as cystic fibrosis. The number of shared genes depends upon the de-gree of relationship. A parent and child, for example, share half of their genes, while first cousins share one in eight of their genes. Ascertaining genetic relatedness gives the nurse the opportunity to offer additional genetic counseling and evaluation. It may also serve as an explanation for families who have a child or individ-ual with a rare autosomal recessive inherited condition (Lea, Jenkins & Francomano, 1998).
When the assessment of family history reveals that the patient has been adopted, genetics-based health assessment becomes more challenging. The nurse and health care team should makeall efforts to help the patient obtain as much information as pos-sible about his or her biological parents, including their ethnic backgrounds.
Questions regarding reproductive history (eg, history of mis-carriage or stillbirth) are included in genetic family history health assessments to identify possible chromosomal conditions. The nurse also inquires about any history of family members with in-herited conditions or birth defects; maternal health conditions such as type 1 diabetes, seizure disorder, or maternal PKU, which may increase the risk for birth defects in children; and exposure to alcohol or other drugs during pregnancy. Maternal age is also noted: women who are 35 years or older who are considering pregnancy and childbearing or who are already pregnant should be offered prenatal diagnosis (eg, testing through amniocentesis) because of the association between advancing maternal age and chromosomal abnormalities such as Down syndrome (Lea, Jenkins & Francomano, 1998).
Assessing ancestry and ethnicity helps identify individuals and groups who could benefit from genetic testing for carrier identi-fication, prenatal diagnosis, and susceptibility testing. For exam-ple, carrier testing for sickle cell anemia is routinely offered to individuals of African-American heritage, while carrier testing for Tay-Sachs disease and Canavan disease is offered to individuals of Ashkenazi Jewish descent. Professional organizations such as the American College of Obstetrics and Gynecology (ACOG, 2001) recommend that relevant racial and ethnic populations be offered carrier testing. Recently, ACOG and the American Col-lege of Medical Genetics (ACMG) recommended that all cou-ples, particularly those of Northern European and Ashkenazi Jewish ancestry, be offered carrier screening for cystic fibrosis (ACOG, 2001). Ideally, carrier testing is offered before conception to allow persons who are carriers to make reproductive decisions. Prenatal diagnosis is offered and discussed when both partners of a couple are found to be carriers.
Inquiring about a patient’s ethnic background is also impor-tant when assessing for susceptibilities to adult-onset conditions such as hereditary breast or ovarian cancer. For example, a spe-cific BRCA1 cancer-predisposing gene mutation seems to occur more frequently in women of Ashkenazi Jewish descent. There-fore, asking about ethnicity can help identify persons with an in-creased risk for certain cancer gene mutations (American Medical Association, 2001).
The nurse assesses ancestry and ethnic background to identify individuals who may have an underlying genetic condition that may affect the safety and efficacy of certain medications or treatments. For example, glucose-6-phosphate dehydrogenase deficiency (G6PD) is a common enzyme abnormality that affects millions of people throughout the world, especially those of Mediterranean, Southeast Asian, African, Middle Eastern, and Near Eastern origin. G6PD is transmitted as a gene mutation on the X chromosome. Individuals with a severe deficiency have chronic hemolytic anemia, while others with a milder deficiency develop hemolytic anemia upon exposure to peroxide-producing drugs, infection, exposure to naphthalene in mothballs, or inges-tion of the fava (broad) bean (Lashley, 1998).
Assessment of ancestry and ethnic background is also impor-tant when considering drug metabolism. The ability to metabolize and eliminate certain medications depends upon acetylation in the liver by the enzyme N-acetyltransferase. Many different versions (polymorphisms) of the gene that codes for N-acetyltransferase exist, and these polymorphisms vary among ethnic groups. This is an important consideration, for example, when isoniazid (INH) is prescribed for the treatment of tuberculosis. Patients who are rapid or ultra-rapid metabolizers have a significantly higher risk for developing isoniazid-induced hepatitis; this is especially true for persons of Chinese and Japanese descent (Lashley, 1998).
Physical assessment may provide clues that a particular genetic condition is present in an individual and family. Family history assessment may offer initial guidance regarding the particular area for physical assessment. For example, a family history of familial hypercholesterolemia would alert the nurse to assess family members for symptoms of hyperlipidemias (xanthomas, corneal arcus, abdominal pain of unexplained origin). As an-other example, a family history of neurofibromatosis type I, an inherited condition involving tumors of the central nervous system, would prompt the nurse to carry out a detailed assess-ment of closely related family members. Skin findings such as café-au-lait spots, axillary freckling, or tumors of the skin (neuro-fibromas) would warrant referral for further evaluation, including genetic evaluation and counseling (Lea, Jenkins & Francomano, 1998).
When a genetic condition is suspected as a result of a family history or physical assessment, the nurse, in collaboration with the health care team, may initiate further discussion and evaluation. Providing genetics information, offering and discussing genetic tests, and suggesting a referral to a geneticist may be performed (Chart 9-4).
When collecting and discussing genetics information, the nurse needs to assess the patient’s and family’s cultural, social, and spir-itual orientations. The nurse also needs to consider the patient’s views about the significance of a genetic condition and its effect on self-concept, as well as the patient’s perception of the role of genetics in health and illness, reproduction, and disability. Pa-tients’ social and cultural backgrounds determine their interpre-tations and values about information obtained from genetic testing and evaluation and thus influence their perceptions of health, illness, and risk. Family structure and decision-making and educational background contribute in the same way (Lea, Jenkins & Francomano, 1998).
Assessing a patient’s beliefs, values, and expectations regard-ing genetic testing and information helps the nurse to provide appropriate information about the specific genetics topic. In some cultures, for example, individuals believe that health means the absence of symptoms and that the cause of illness is supernatural. Patients with these beliefs may initially reject suggestions for presymptomatic or carrier testing. However, by including re-sources such as family, cultural, and religious community leaders when providing genetics-related health care, the nurse can help ensure that patients receive information in a way that tran-scends social, cultural, and economic barriers (Lea, Jenkins & Francomano, 1998).
Psychosocial assessment is an essential nursing component of the genetics health assessment (Chart 9-5). After conducting an ini-tial psychosocial assessment, the nurse will be aware of the po-tential impact of new genetic information on the patient and family and how they may cope with this information.