Home > Newborn Disorders > 2M3HBA deficiency
2M3HBA deficiency
Screening
Names
2M3HBA deficiency
2-methyl-3-hydroxybutyryl-CoA dehydrogenase deficiency
MHBD deficiency
hydroxyl-CoA dehydrogenase deficiency
3-hydroxy-2-methylbutyryl-CoA dehydrogenase (3H2MBD) deficiency
2-methyl-3-hydroxybutyric acidemia
Overview
Deficiency of this mitochondrial enzyme results in impaired oxidation of certain fatty acids and isoleucine, with resultant accumulation of organic acids.Prevalence
fewer than 10 reported cases [2M3HBA deficiency fact sheet (Iowa Dept. of Health) (
21 KB)
]
Clinical Characteristics
With treatment, deterioration may be avoided, and some improvement may result. Without treatment, progressive loss of skills and neurologic impairment, mental retardation and seizures can be expected. Symptom onset has generally been between 9 and 14 months and may be aggravated by stress or illness.Initial signs/symptoms may include:
- poor feeding,
- spasticity,
- lethargy,
- lab findings:
- lactic acidosis.
If not treated promptly, patients may experience:
- choreoathetosis,
- progressive loss of motor skills,
- hearing loss,
- retinal degeneration,
- seizures,
- brain damage, and
- death.
Follow-up on positive screening test
Quantitative plasma acylcarnitine profile, urine organic acids, enzyme assay in fibroblasts.Primary care management
Upon notification of the + screen
- contact the family and evaluate the infant for poor feeding, vomiting, or lethargy;
- Provide emergency treatment/referral for symptoms of hypoglycemia, metabolic acdosis, or seizures;
- To confirm the diagnosis, work with the following service(s): Utah Newborn Screening Program, (801-584-8256); See also Services below;
- For evaluation and ongoing collaborative management, consult the following service(s): Medical Genetics, (801-231-3599); See also Services below;
If the diagnosis is confirmed
- 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, developmental and educational interventions.
Specialty Care Collaboration
Initial consultation and ongoing collaboration, particularly for dietary management. Genetic counseling for the family.Resources
Information & Support
For Professionals
ACT Sheet for Elevated C5-OH Acylcarnitine (ACMG)
( 400 KB)
Developed by the American College of Medical Genetics, includes recommended responses to positive newborn screening test results,
diagnostic evaluation, clinical expectations, and sources of additional information.
ACT Sheets and Confirmatory Algorithms (ACMG)
The American College of Medical Genetics (ACMG) has developed ACTion (ACT) Sheets and algorithms for responding to positive
newborn screening test results. This page contains a table with links to all of the ACT Sheets and related algorithms.
Resources for 2M3HBA deficiency (NLM)
Comprehensive compilation of links to information, articles, research, case studies, genetics, and more; from the National
Library of Medicine and the Genetic Alliance.
2M3HBA deficiency (OMIM)
From the Online Mendelian Inheritance in Man site, hosted by Johns Hopkins University, providing technical information for
providers on genetic disorders, links to MEDLINE, and links to other scientific information and sites.
2M3HBA deficiency fact sheet (Iowa Dept. of Health)
( 21 KB)
This fact sheet, developed by the Iowa Department of Health, provides information for parents and professionals.
For Parents and Patients
2M3HBA deficiency (Genetics Home Reference)
Excellent, detailed review aimed at patients and families from the National Library of Medicine's Genetics Home Reference
site.
Organic Acidemia Association (OAA)
A non-profit organization that provides information for parents and providers; newsletters; event information; connections
with other parents; a listserv; a discussion board; information about nutrition and recipes; translation of their web pages
into five other languages; hosting of the Propionic Acidemia Research Network and other research funds; and links to other
sites.
National Newborn Screening & Genetics Resource Center
Provides information for families and professionals about genetic screening; links to support and advocacy groups; links to
state genetic contacts; newsletters; fact sheets; data reports; publications; and more.
Services
Newborn Screening Programs
Utah Newborn Screening Program,
more info...
44 Mario Capecchi Drive
Salt Lake City, UT 84114
Phone: 801-584-8256
Fax: 801-536-0966
http://health.utah.gov/newbornscreening
Pediatric Medical Genetics
See all Pediatric Medical Genetics services providers (3) in our database.
For other services related to this condition, browse our Services categories or search our database.
Authors
| Author: | Nicola Longo MD, PhD, 3/2007 |
| Compiled and edited by: | Alfred Romeo RN, PhD, 3/2007 |
| Content Last Updated: | 7/2010 |