Prenatal care: Medical management of potentially problematic pregnancies identified through abnormal maternal screening, ultrasound, or family history may include specific genetic testing and realistic information about fetal abnormalities to allow parents to make informed decisions about pregnancy continuation.
Newborn screening to detect preventable, common, or treatable disease.
Investigation of fetal death, stillbirth, or miscarriage.
Decisive diagnosis: Diagnostic and presymptomatic studies may be done to investigate certain syndromes or diseases related to chromosomal or single gene disorders, for gene status in the diagnosis of cancer, for inherited diseases in carrier status, and to test relatives with no symptoms at risk for developing significant medical or reproductive problems. As a general rule, presymptomatic testing is not offered to minors.
Cytogenetic analysis or DNA probes are used to study bone marrow and to check for diagnostic translocations, particularly in leukemias (cells with genetic changes).
Assignment of gender in the presence of ambiguous genitalia.
Genetic counseling: To address prognosis and diagnosis as well as causes and recurrence risks in the context of the family as well as individuals. Genetic counseling often depends on precise testing or chromosomal analysis.
Clinical Alert
Tests are not performed purely for information’s sake; instead, they are ordered for diagnostic purposes in symptomatic individuals after testing implications are explained for conditions for which treatment is available or in situations in which treatment would be useless.
Genetic counseling ideally should be available before and after testing and linked to management (proper medications, diets, hormone replacement) and to educational and age-appropriate therapy programs.
Patients should be able to use test results to make their own informed decisions about issues such as childbearing and medical treatment. Privacy is an issue in genetic testing.
Everyone carries genes that are potentially harmful or defective to some degree; genetic counseling can put these risks into perspective.
Family history along with the medical and personal health records are major tools in identifying genetic disorders.
Recognize and document signs of possible genetic disorders:
Birth defects: Cleft palate, congenital heart disease
Dysmorphic features: Abnormally shaped or low-set ears, extra fingers or toes, large tongue, upward slanting of eyes, flattened face, characteristic features of Down syndrome, hypopigmentation of skin, abnormal color of urine, brittle hair
Growth problems: Short stature (found in Down syndrome and Turner syndrome), tall stature (found in Marfan syndrome)
Developmental delay: Failure to thrive, late achievement of walking or talking, hypotonia
Sensory deficits: Early-onset hearing loss or visual impairment; vomiting with hypoglycemia (suggests galactosemia [GAL]); also, many metabolic disorders only become apparent during recurrent fever and infections
Adult intellectual disability: Fragile X syndrome; long face; prominent ears, jaw, and forehead in persons (usually male) with undiagnosed intellectual disability