Malonic Acidemia
Other Names
MA
Malonyl-CoA decarboxylase deficiency
Malonyl-coenzyme A decarboxylase deficiency
Malonic aciduria
MLYCD
MCD
Overview
Insufficient malonyl-CoA decarboxylase results in the accumulation of malonic acid and its derivatives in the blood. Malonic acid inhibits fatty acid oxidation, resulting in hypoglycemia, and potentially causing cardiomyopathy. Treatment involves carnitine supplementation, a low-fat diet supplemented with medium chain triglycerides (oxidation is not inhibited by malonic acid), and avoidance of fasting. [Wightman: 2003]Incidence
Fewer than 30 cases have been reported. [Genetics: 2017]Clinical Characteristics
With treatment, some of the sequelae may be prevented or ameliorated. Without treatment, episodes of hypoglycemia and metabolic acidosis may lead to delayed development, hypotonia, seizures, and cardiomyopathy. While symptoms may present within the first few weeks of life, symptoms are more likely to develop in older infants and children. Symptoms may be triggered by fasting and illness. Developmental delays and hypotonia can be seen even with optimal treatment and without any episode of decompensation.Initial symptoms/signs may include:
- Hypotonia
- Cardiomyopathy
- Seizures
- Vomiting
- Poor feeding
- Diarrhea
- Lethargy
- Hypoglycemia
- Lactic acidosis
Follow-up Testing after Positive Screen
Quantitative plasma acylcarnitine profile, urine organic acids (elevated malonic acid)Primary Care Management
Upon Notification of the + Screen
- Contact the family and evaluate the infant for vomiting, poor feeding, lethargy, and ketonuria.
- Provide emergency treatment/referral for evidence of hypoglycemia, acidosis, or seizures.
- To confirm the diagnosis, work with the following service(s): Newborn Screening Services (see NW providers [2]).
- For evaluation and ongoing collaborative management, consult the following service(s): Pediatric Genetics (see NW providers [1]).
If the Diagnosis is Confirmed
- Educate the family regarding signs, symptoms, and the need for urgent care when the infant becomes ill.
- Support implementation and maintenance of a high-carbohydrate, low-fat diet with medium chain triglyceride supplements. Oral L-carnitine is indicated.
- Promptly treat infections, fever, and gastroenteritis with IV fluids containing glucose and admit to hospital.
- For those identified after irreversible consequences, assist in management, particularly with developmental and educational interventions.
Specialty Care Collaboration
Provide initial consultation and ongoing collaboration, particularly for dietary management. Facilitate genetic counseling for the family.Resources
Information & Support
For Professionals
Malonic Aciduria (OMIM)
Extensive review of literature that provides technical information on genetic disorders; Online Mendelian Inheritance in Man
site, hosted by Johns Hopkins University.
Genetics in Primary Care Institute (AAP)
Contains health supervision guidelines and other useful resources for the care of children with genetic disorders; American
Academy of Pediatrics.
For Parents and Patients
Malonic Aciduria (Genetics Home Reference)
Excellent, detailed review of the condition for patients and families; sponsored by the U.S. National Library of Medicine.
Baby's First Test: Malonic Aciduria (Genetic Alliance)
Information about early signs, follow-up testing, treatment, accessing care, and expected outcomes. Provides links to support
services.
Organic Acidemia Association (OAA)
A nonprofit organization that provides information, support, events, connections with other parents, a discussion board,
and nutrition and recipe ideas.
National Newborn Screening and Global Resource Center (NNSGRC)
Provides information about each state's newborn screening programs; sponsored by the University of Texas Health Science Center
at San Antonio, Department of Pediatrics.
Tools
ACT Sheet for Malonic Aciduria (Elevated C3-DC) (ACMG) (
347 KB)
Contains short-term recommendations for clinical follow-up of the newborn who has screened positive; American College of Medical
Genetics.
Confirmatory Algorithm for Malonic Aciduria (Elevated C3-DC) (ACMG) ( 53 KB)
Resource for clinicians to help confirm diagnosis; American College of Medical Genetics.
Services Nationwide
Newborn Screening Services
See all Newborn Screening Services services providers (2) in our database.
For other services related to this condition, browse our Services categories or search our database.
Helpful Articles
PubMed search for malonic aciduria in children
Footitt EJ, Stafford J, Dixon M, Burch M, Jakobs C, Salomons GS, Cleary MA.
Use of a long-chain triglyceride-restricted/medium-chain triglyceride-supplemented diet in a case of malonyl-CoA decarboxylase
deficiency with cardiomyopathy.
J Inherit Metab Dis.
2010.
PubMed abstract
Page Bibliography
Genetics Home Reference.
Malonyl-CoA decarboxylase deficiency.
U.S. Library of Medicine; (2017)
https://ghr.nlm.nih.gov/condition/malonyl-coa-decarboxylase-deficiency.... Accessed on June 2017.
Wightman PJ, Santer R, Ribes A, Dougherty F, McGill N, Thorburn DR, FitzPatrick DR.
MLYCD mutation analysis: evidence for protein mistargeting as a cause of MLYCD deficiency.
Hum Mutat.
2003;22(4):288-300.
PubMed abstract