Growing consumer awareness and the increasing availability of genetic tests for many conditions is likely increasing the number of questions your patients are asking about their risk of disease, the risk to their offspring and whether genetic testing is right for them. Genetic counselors can help you address your patients’ needs and incorporate genetics and genomics into your practice.
1. What is metabolic genetics?
Metabolic genetics is a medical specialty that focuses on the diagnosis, treatment, and long term follow-up of patients with inborn errors of metabolism. These conditions include: disorders of amino acid and organic acid metabolism, fatty acid oxidation disorders, glycogen storage disorders, peroxisomal disorders, urea cycle disorders, disorders of carbohydrate metabolism and transport, disorders of creatine metabolism and transport, mitochondrial disorders and lysosomal storage disorders. There are hundreds of different inborn errors of metabolism. Although individually rare, inborn errors of metabolism collectively account for approximately 15% of single gene disorders.
2. Who should I refer to a metabolic genetic counselor?
- Infants with suspected metabolic disease due to an abnormal newborn screen
- Infants and children with failure to thrive, growth and developmental delays, autism, or intolerance to certain foods (protein, fructose, etc.)
- Infants, children, or adults with regression of motor, cognitive or language skills
- Children and adults with a known or suspected inborn error of metabolism
- Couples with a family history of inborn errors of metabolism who wish to know their risk of having an affected child
- Couples who have children that died of sudden infant death syndrome (SIDS) or sudden unexplained death in childhood (SUDC)
3. What benefit does a metabolic genetic counselor provide to my patients (PCP and/or specialist)?
A metabolic genetic counselor works with geneticists, registered dieticians, nurses and other allied health professionals to provide quality care for a patient with an inborn error of metabolism. The role of a metabolic genetic counselor is to assist in the assessment of an inborn error of metabolism, act as an advocate for the patient through the process of the metabolic genetics evaluation, and help him/her understand what a diagnosis of an inborn error of metabolism means for each family member, both personally and medically. A metabolic genetic counselor obtains a complete family, medical and prenatal/birth history, identifies who in the family is at risk for an inherited inborn error of metabolism and discusses screening and prevention options for those individuals. The counselor helps explain the testing process, results, and details about the specific diagnosed disease, including its inheritance, treatment, and risk of recurrence. Metabolic genetic counselors will also facilitate referrals to outside resources, such as community agencies and family support groups, and in some cases, they will assist in case management and long- term coordination of care for patients with complex metabolic conditions.
4. What evidence is there to recommend or support genetic counseling in metabolic genetics? (i.e. list Practice Guidelines, Publications, and Policies that recommend and support genetic counseling in this clinical area and we will hyperlink to them on the NSGC website if they’re available online or include a PDF document)?
The following publications and guidelines support the use of genetic counseling:
Hartley JN et al, J Genet Couns 2011 Feb: 20(1): 20-22. Genetic Counseling in a Busy Pediatric Metabolic Practice.
Kishnani PS et al, Genet Med 2010:12(7):446–463. Newborn screening fact sheets published in Pediatrics, September 6, 2006
O’Shea R et al, J Genet Couns 2011 Apr: 20(2):192-203. Communication of genetic information by other health professionals: the role of the genetic counsellor in specialist clinics.
Phenylketonuria: Screening and Management; NIH Consensus Development and Conference Statement: http://consensus.nih.gov/2000/2000phenylketonuria113html.htm
Management Guidelines for Mucopolysaccharidosis VI: http://pediatrics.aappublications.org/cgi/reprint/120/2/405
Mucopolysaccharidosis I: Management and Treatment Guidelines: http://pediatrics.aappublications.org/cgi/reprint/123/1/19
ACMG Practice Guidelines: Pompe disease diagnosis and management guidelines: http://journals.lww.com/geneticsinmedicine/pages/articleviewer.aspx?year=2006&issue=05000&article=00001&type=abstract
Multidisciplinary Management of Hunter Syndrome: http://www.pediatrics.org/cgi/content/full/124/6/e1228
Newborn Screening for Krabbe Disease: the New York State Model
5. What do I tell my patient about a referral to metabolic genetics (what to expect during the appointment, what questions will be asked, what topics will be discussed, how the appointment will be valuable to them)?
Typically, an appointment in metabolic genetics begins with metabolic genetic counselor asking detailed questions about the prenatal/birth history, family history, and medical history of the patient. The counselor may ask questions about family members living or deceased who required a special diet, had mental retardation, seizures, or sudden death. The geneticist will review this information and perform a physical exam. Once a specific diagnosis is suspected, the geneticist or genetic counselor will explain the details of this diagnosis and the process of testing (genetic, biochemical, or other) for the condition. A metabolic genetic counselor can also offer support and counseling to address psychosocial issues that may arise when a genetic condition is identified in a family and provide literature and other resources for the family to review. A metabolic genetics visit is the appropriate way to learn if an inborn error of metabolism is contributing to neurological or developmental problems and an excellent way to receive comprehensive care and management for an inborn error of metabolism once a diagnosis is made.
6. Where can I find a genetic counselor specializing in metabolic genetics?
Search the NSGC Find a Genetic Counselor Directory and select Metobolic Genetics under type of specialty.