Genetic Counseling
Genetic counseling is the communication process of providing information and support to individuals and families with a diagnosis and/or risk of occurrence of an inherited disorder. Culturally sensitive genetic counseling, with an emphasis on reproductive issues, is an integral and necessary component of comprehensive care for patients and parents affected by all forms of thalassemia disease and trait. Services should be provided by a licensed genetic counselor in states with licensure legislation and by an ABGC board-certified or board-eligible genetic counselor in all other states.
Genetic counseling is needed:
- at diagnosis and during adolescence
- prior to and after any genetic testing
- prior to pregnancy and/or as early in pregnancy as possible
- Annual follow-ups are needed to reinforce teaching.
Critical components of genetic counseling include:
- obtaining a three-generation genetic family history (pedigree)
- assessing risk for thalassemia in family members
- identifying risk factors impacting medical management (e.g., family history of other hemoglobin traits or diseases, hereditary hemochromatosis, G6PD deficiency, inherited thrombophilia, cardiovascular disease or its risk factors, cardiac conduction defects, diabetes, renal disease, ophthalmologic disorders, hearing loss, allergies, ethnicity, consanguinity)
- incorporating psychosocial information impacting the family system and relationships (e.g., location of residence, disclosure/nondisclosure of diagnosis, reliable source of emotional/social support)
- assisting patients in conveying information about genetic risk to other family members
- providing informed consent, pre-, and post-counseling for all genetic testing
- alpha-globin genotyping: hemoglobin H–Constant Spring and other structural alphaglobin variants, possible modifying effects of alpha-globin deletions/triplications on betathalassemia
- beta-globin genotyping: beta0/beta+, S, D, E, O, and other structural variants
The limitations of drawing genotype/phenotype correlations include:
- developmentally appropriate consent/education for minors
- reproductive genotype post–stem cell transplant or bone marrow transplant
- the possibility of revealing undisclosed adoption or alternative paternity
- discussing/facilitating appropriate screening and diagnostic tests for relatives
Genetic Testing
If HLA typing is performed when stem cell transplant or bone marrow transplant is an option, genetic counseling and education is vital due to ethical implications. A genetic counselor should provide initial and ongoing teaching regarding natural history and clinical manifestations; signs and symptoms of disease that warrant immediate medical attention; and available emotional and social support services. Genetic counselors should also provide available resources in collaboration with outreach coordinators and social workers (e.g., research studies, support groups, advocacy organizations, and patient-to-patient or parent-to-parent connections).
