Inborn Errors of Metabolism Follow-up

Author: Debra L Weiner, MD, PhD; Chief Editor: Richard G Bachur, MD more...

Updated: Mar 13, 2012

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Further Inpatient Care
Further Outpatient Care
Transfer
Deterrence/Prevention
Complications
Prognosis
Patient Education
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Tables

References

Further Inpatient Care

Once toxic metabolites have been normalized, protein can be reintroduced using an essential amino acid solution, initially at 0.5-0.75 g/kg/d and gradually increased.
- For amino and organic acidopathies and urea cycle defects, protein intake should be restricted to 40-50% of recommended daily allowance (RDA).
  - Lipids, 2-3 g/kg/d as 20% intralipid, can be given to increase caloric intake, but they are contraindicated for certain fatty acid oxidation defects.
  - For patients able to tolerate enteral feeding, protein-restricted preparations (eg, Meade Johnson 80056) may be given.
  - With definitive diagnosis, specific dietary regimens, available for most inborn errors of metabolism (IEMs), should be initiated.
Pharmacologic therapy to increase activity of abnormal cofactor-dependent enzymes (eg, thiamine [B-1] 5-20 mg/d PO up to 500 mg/d, biotin 5-20 mg/d PO, riboflavin [B-2] 200-300 mg PO tid, cobalamin [B-12] 1-2 mg/d IM) may be given. Vitamins may be given empirically.
Transplantation (organ or bone marrow)
Enzyme replacement therapy
Gene therapy

Further Outpatient Care

Medical therapy specific for the inborn error of metabolism diagnosed will need to be continued, usually for life.^{[7, 8]}

Long-term, routine follow-up screening should be provided for potential disease complications.

Transfer

Patients may require transfer to a tertiary care facility for further evaluation and treatment.

Treatment to stabilize the patient should be initiated prior to transfer.
Do not delay treatment to arrange transfer.
When selecting the mode of transport and transport team, keep in mind that patients may deteriorate rapidly.

Deterrence/Prevention

Strict adherence to dietary and pharmacologic regimen is recommended for patients diagnosed with an inborn error of metabolism.

Early treatment symptoms and recognition that physiologic stressors, including intercurrent illness, trauma, surgery, and changes in diet may precipitate symptoms, is important in avoiding metabolic decompensation.

Complications

Complications of metabolic diseases may include the following:

Significant neurologic impairment
Death

Prognosis

Prognosis varies based on individual inborn error of metabolism (IEM) and may differ for different forms of a particular IEM.

A high index of suspicion is critical for early diagnosis and treatment of IEM.

Rapid treatment may be life saving and often results in full recovery.

Patient Education

Provide education regarding disease and patient care (manifestations, course of disease, treatment, psychosocial support) as appropriate.

Provide genetic counseling to discuss recurrence risks, screening of other family members, and prenatal diagnosis.

Provide information regarding support groups. National Organization of Rare Diseases (NORD) can direct families to resources for more than 1000 IEMs. Professional and peer support groups exist for many IEMs.

Contributor Information and Disclosures

Author

Debra L Weiner, MD, PhD Attending Physician, Division of Emergency Medicine, Children's Hospital, Boston; Assistant Professor, Department of Pediatrics, Harvard Medical School

Disclosure: Nothing to disclose.

Specialty Editor Board

Garry Wilkes MBBS, FACEM, Director of Emergency Medicine, Calvary Hospital, Canberra, ACT; Adjunct Associate Professor, Edith Cowan University; Clinical Associate Professor, Rural Clinical School, University of Western Australia

Disclosure: Nothing to disclose.

Mary L Windle, PharmD Adjunct Associate Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Nothing to disclose.

Wayne Wolfram, MD, MPH Associate Professor, Department of Emergency Medicine, Mercy St Vincent Medical Center

Wayne Wolfram, MD, MPH is a member of the following medical societies: American Academy of Emergency Medicine, American Academy of Pediatrics, and Society for Academic Emergency Medicine

Disclosure: Nothing to disclose.

John D Halamka, MD, MS Associate Professor of Medicine, Harvard Medical School, Beth Israel Deaconess Medical Center; Chief Information Officer, CareGroup Healthcare System and Harvard Medical School; Attending Physician, Division of Emergency Medicine, Beth Israel Deaconess Medical Center

John D Halamka, MD, MS is a member of the following medical societies: American College of Emergency Physicians, American Medical Informatics Association, Phi Beta Kappa, and Society for Academic Emergency Medicine

Disclosure: Nothing to disclose.

Chief Editor

Richard G Bachur, MD Associate Professor of Pediatrics, Harvard Medical School; Associate Chief and Fellowship Director, Attending Physician, Division of Emergency Medicine, Children's Hospital of Boston

Richard G Bachur, MD is a member of the following medical societies: American Academy of Pediatrics, Society for Academic Emergency Medicine, and Society for Pediatric Research

Disclosure: Nothing to disclose.

References

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Table 1. Clinical and Laboratory Findings of Inborn Errors of Metabolism

Table 1. Clinical and Laboratory Findings of Inborn Errors of Metabolism

Clinical Findings*	AA	OA	UCD	CD	GSD	FAD	LSD	PD	MD
Episodic decompensation	X	+	++	+	X	+	-	-	X
Poor feeding, vomiting, failure to thrive	X	+	++	+	X	X	+	+	+
Dysmorphic features and/or skeletal or organ malformations	X	X	-	-	X	X	+	X	X
Abnormal hair and/or dermatitis	-	X	X	-	-	-	-	-	-
Cardiomegaly and/or arrhythmias	-	X	-	-	X	X	+	-	X
Hepatosplenomegaly and/or splenomegaly	X	+	+	+	+	+	+	X	X
Developmental delay +/- neuroregression	+	+	+	X	X	X	++	+	+
Lethargy or coma	X	++	++	+	X	++	-	-	X
Seizures	X	X	+	X	X	X	+	+	X
Hypotonia or hypertonia	+	+	+	+	X	+	X	+	X
Ataxia	-	X	+	X	-	X	X	-	-
Abnormal odor	X	+	X	-	-	-	-	-	-
Laboratory Findings*
Primary metabolic acidosis	X	++	+	+	X	+	-	-	X
Primary respiratory alkalosis	-	-	+	-	-	-	-	-	-
Hyperammonemia	X	+	++	X	-	+	-	-	X
Hypoglycemia	X	X	-	+	X	+	-	-	X
Liver dysfunction	X	X	X	+	X	+	X	X	X
Reducing substances	X	-	-	+	-	-	-	-	-
Ketones	A	H	A	A	L/A	L	A	A	H/A
*Within disease categories, not all diseases have all findings. For disorders with episodic decompensation, clinical and laboratory findings may be present only during acute crisis. For progressive disorders, findings may not be present early in the course of disease. ++ = Always present. + = Usually present. X = Sometimes present. - = Absent. H = Inappropriately high. L = Inappropriately low. A = Appropriate.

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