2M3HBA Deficiency
Guidance for primary care clinicians receiving a positive newborn screen result
Screening
Description
With 2M3HBA deficiency, the deficiency of this mitochondrial enzyme results in impaired oxidation of certainfatty acids and isoleucine, with resultant accumulation of organic acids.
Clinical Characteristics
- Poor feeding
- Spasticity
- Lethargy
- Lab findings:
- Lactic acidosis
- Choreoathetosis
- Progressive loss of motor skills
- Hearing loss
- Retinal degeneration
- Seizures
- Brain damage
- Death
Incidence
Primary Care Management
Next Steps After a Positive Screen
- Contact the family and evaluate the infant for poor feeding, vomiting, or lethargy.
- Provide emergency treatment/referral for symptoms of hypoglycemia, metabolic acidosis, or seizures.
Confirming the Diagnosis
- To confirm the diagnosis of 2M3HBA deficiency, work with Newborn Screening Services (see NW providers [1]).
- Follow-uptesting will include quantitative plasma acylcarnitine profile, urine organic acids,andenzyme assay in fibroblasts.
If the Diagnosis is Confirmed
- For evaluation and ongoing collaborative management, consult Medical Genetics (see NW providers [1]).
- A dietician may work with the family to devise an optimal approach to dietary management. See Nutrition, Metabolic (see NW providers [11]).
- Refer the family to Genetic Testing and Counseling (see NW providers [6]).
- Educate the family regarding signs, symptoms, and the need for urgent care when the infant becomes ill.
- Isoleucine and protein restriction, treatment of acute episodes with glucose and fluids.
- For those identified after irreversible consequences, assist in management, particularly with low vision aids, hearing aids or cochlear implants, and developmental and educational interventions, such as Early Intervention for Children with Disabilities/Delays (see NW providers [3]).
Resources
Information & Support
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
2M3HBA 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
Tools
ACT Sheet for Elevated C5-OH Acylcarnitine (ACMG) (
336 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 Nationwide (NW)
| Service Categories | # of providers* in: | NW | Partner states (4) (show) | | NM | NV | RI | UT | |
|---|---|---|---|---|---|---|---|---|---|
| Early Intervention for Children with Disabilities/Delays | 3 | 34 | 31 | 13 | 51 | ||||
| Genetic Testing and Counseling | 6 | 6 | 12 | 8 | 12 | ||||
| Medical Genetics | 1 | 2 | 5 | 4 | 7 | ||||
| Newborn Screening Services | 1 | 3 | 2 | 2 | 3 | ||||
| Nutrition, Metabolic | 11 | 11 | 13 | 13 | 11 | ||||
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.
Page Bibliography
Zschocke J.
HSD10 disease: clinical consequences of mutations in the HSD17B10 gene.
J Inherit Metab Dis.
2012;35(1):81-9.
PubMed abstract