Get Help in Rhode IslandBeta-Ketothiolase Deficiency (BKD)
Guidance for primary care clinicians receiving a positive newborn screen result
Screening
Description
Due to the absence of the enzyme mitochondrial acetoacetyl-CoA thiolase, individuals with beta-ketothiolase deficiency are unable to break down the amino acid isoleucine and utilize ketone bodies. This results in a buildup of organic acids (ketones) and a decreased ability to generate energy. Patients typically present with metabolic acidosis induced by fasting, infection, fever, or vomiting.
Clinical Characteristics
Without treatment, outcomes can vary widely due to broad clinical heterogeneity with death or severe neurologic impairment possible, particularly in those with severe episodes in infancy. Age of symptom onset ranges from 3 days to 4 years, with the mean age at presentation of 15 months. Symptoms are usually triggered by fasting and illness.
- Feeding problems
- Vomiting
- Diarrhea
- Lethargy progressing to coma
- Hypoglycemia or occasionally hyperglycemia
- Acute metabolic acidosis
- Failure to thrive
- Intellectual disability
- Death
Primary Care Management
Next Steps After a Positive Screen
- Contact the family and evaluate the infant for poor feeding, vomiting, and lethargy.
- Provide emergency treatment/referral for symptoms of hypoglycemia, ketonuria, or acidosis.
Confirming the Diagnosis
- To confirm the diagnosis of beta-ketothiolase deficiency, work with Newborn Screening Services (see RI providers [2]).
- Follow-up testing will include quantitative plasma acylcarnitine profile, serum biotinidase assay, urine organic acids. Not all patients will have identifiable biochemical abnormalities at time of follow-up, and DNA testing might be indicated. Patients with milder variants can be missed by newborn screening or have elevation of other acylcarnitine species.
If the Diagnosis is Confirmed
- For evaluation and ongoing collaborative management, consult Biochemical Genetics (Metabolics) (see RI providers [3]).
- Educate the family regarding signs, symptoms, and the need for urgent care when the infant becomes ill.
- Avoidance of fasting; frequent, low-protein, high-carbohydrate meals. Uncooked cornstarch before bedtime might be indicated in some cases.
- Some patients tend to spontaneously restrict proteins as they get older.
- Oral L-carnitine may be indicated for some affected children.
- Bicarbonate and intravenous glucose need to be utilized during metabolic crisis.
- Monitor urine ketone levels when the child is sick or unable to eat.
- For those identified after irreversible consequences, assist in management, particularly with developmental and educational interventions.
Resources
Information & Support
Related Portal Content
After a Diagnosis or Problem is Identified
Families can face a big change when their baby tests positive for
a newborn condition. Find information about A New Diagnosis - You Are Not Alone;
Caring for Children with Special Health Care Needs; Assistance in Choosing
Providers; Partnering with Healthcare Providers; Top Ten Things to Do After a
Diagnosis.
For Professionals
Beta-Ketothiolase Deficiency (OMIM)
Information about clinical features, diagnosis, management, and molecular and population genetics; Online Mendelian Inheritance
in Man, authored and edited at the McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine
For Parents and Patients
Beta-Ketothiolase Deficiency - Information for Parents (STAR-G)
A fact sheet, written by a genetic counselor and reviewed by metabolic and genetic specialists, for families who have received
an initial diagnosis of this newborn disorder; Screening, Technology and Research in Genetics.
Beta-Ketothiolase Deficiency (MedlinePlus)
Information for families that includes description, frequency, causes, inheritance, other names, and additional resources;
from the National Library of Medicine.
Organic Acidemia Association (OAA)
A nonprofit organization that provides information, support, events, connections with other parents, a discussion board,
and nutrition and recipe ideas.
Resources for Beta-Ketothiolase Deficiency (Disease InfoSearch)
Compilation of information, articles, and links to support; from Genetic Alliance.
Tools
RI ACT Sheet for ß-ketothiolase (BKT) deficiency (ACMG) (
128 KB)
Contains short-term recommendations for clinical follow-up of the newborn who has screened positive, along with resources
for consultation and patient education/support; from the American College of Genetics and Genomics
Confirmatory Algorithms for Elevated C5-OH (ACMG) ( 224 KB)
Basic steps involved in determining the final diagnosis of an infant with a positive newborn screen for this condition; American
College of Medical Genetics.
Services for Patients & Families in Rhode Island (RI)
| Service Categories | # of providers* in: | RI | NW | Other states (3) (show) | | NM | NV | UT |
|---|---|---|---|---|---|---|---|---|
| Biochemical Genetics (Metabolics) | 3 | 1 | 1 | 2 | 2 | |||
| Medical Genetics | 4 | 1 | 2 | 5 | 7 | |||
| Newborn Screening Services | 2 | 1 | 3 | 2 | 3 | |||
For services not listed above, browse our Services categories or search our database.
* number of provider listings may vary by how states categorize services, whether providers are listed by organization or individual, how services are organized in the state, and other factors; Nationwide (NW) providers are generally limited to web-based services, provider locator services, and organizations that serve children from across the nation.
Helpful Articles
PubMed search for newborn screening and beta-ketothiolase deficiency, last 10 years.
Pasquali M, Monsen G, Richardson L, Alston M, Longo N.
Biochemical findings in common inborn errors of metabolism.
Am J Med Genet C Semin Med Genet.
2006;142C(2):64-76.
PubMed abstract
Korman SH.
Inborn errors of isoleucine degradation: a review.
Mol Genet Metab.
2006;89(4):289-99.
PubMed abstract
Page Bibliography
Korman SH.
Inborn errors of isoleucine degradation: a review.
Mol Genet Metab.
2006;89(4):289-99.
PubMed abstract
Pasquali M, Monsen G, Richardson L, Alston M, Longo N.
Biochemical findings in common inborn errors of metabolism.
Am J Med Genet C Semin Med Genet.
2006;142C(2):64-76.
PubMed abstract