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Inborn Errors of Metabolism Follow-up

  • Author: Debra L Weiner, MD, PhD; Chief Editor: Stephen Kemp, MD, PhD  more...
Updated: Feb 18, 2015

Further Outpatient Care

Medical therapy specific for the inborn error of metabolism diagnosed will need to be continued, usually for life.[7, 9]

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


Further Inpatient Care

Further inpatient care may include the following:

  • 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


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.


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 of metabolic diseases may include the following:

  • Significant neurologic impairment
  • Death


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

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

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 Professor, Department of Emergency Medicine, Mercy St Vincent Medical Center; Chairman, Pediatric Institutional Review Board, Mercy St Vincent Medical Center, Toledo, Ohio

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

Disclosure: Nothing to disclose.

Chief Editor

Stephen Kemp, MD, PhD Former Professor, Department of Pediatrics, Section of Pediatric Endocrinology, University of Arkansas for Medical Sciences College of Medicine, Arkansas Children's Hospital

Stephen Kemp, MD, PhD is a member of the following medical societies: American Academy of Pediatrics, American Association of Clinical Endocrinologists, American Pediatric Society, Endocrine Society, Phi Beta Kappa, Southern Medical Association, Southern Society for Pediatric Research

Disclosure: Nothing to disclose.

Additional Contributors

Garry Wilkes, MBBS, FACEM Director of Clinical Training (Simulation), Fiona Stanley Hospital; Clinical Associate Professor, University of Western Australia; Adjunct Associate Professor, Edith Cowan University, Western Australia

Disclosure: Nothing to disclose.

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Table 1. Clinical and Laboratory Findings of Inborn Errors of Metabolism
Clinical Findings* AA OA UCD CD GSD FAD LSD PD MD
Episodic decompensationX++++X+--X
Poor feeding, vomiting, failure to thriveX++++XX+++
Dysmorphic features and/or skeletal or organ malformationsXX--XX+XX
Abnormal hair and/or dermatitis-XX------
Cardiomegaly and/or arrhythmias-X--XX+-X
Hepatosplenomegaly and/or splenomegalyX++++++XX
Developmental delay +/- neuroregression+++XXX++++
Lethargy or comaX+++++X++--X
Hypotonia or hypertonia++++X+X+X
Abnormal odorX+X------
Laboratory Findings*         
Primary metabolic acidosisX++++X+--X
Primary respiratory alkalosis--+------
Liver dysfunctionXXX+X+XXX
Reducing substancesX--+-----
*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.

AA = Amino acidopathy

OA = Organic acidopathy

UCD = Urea cycle defect

CD = Carbohydrate disorder

GSD = Glycogen storage disorder

FAD = Fatty acid oxidation defect

LSD = Lysosomal storage disease

PD = Peroxisomal disorder

MD = Mitochondrial disorder

++ = Always present

+ = Usually present

X = Sometimes present

- = Absent

H = Inappropriately high

L = Inappropriately low

A = Appropriate

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