Amino Acid Profile and Lactate Pyruvate Ratio: Potential Adjunct Markers for Differentiating Inborn Errors of Metabolism

  • Prajna P. Shetty
  • K. Nagendra
  • K. NaliniEmail author
  • Pragna Rao
  • Nalini Bhaskaranand
  • Vijetha Shenoy Belle
Original Research Article


Inborn errors of metabolism (IEM) lead to the physical and mental disability and death of infants, which can be prevented if treated early. Hence it is imperative in diagnosing these disorders at the earliest. The study is planned to differentiate suspected IEM by quantifying the lactate–pyruvate ratio (L/P ratio), Amino acid profiling by HPLC in addition to blood ammonia using the basic methodology in comparison to globally accepted mass spectroscopy technique and specific enzyme activity assays. The objective of this study is not to compete with the existing gold standard methodology rather makes the best of basic diagnostic modalities available. Five cases out of 100 referred cases of IEM suspicion showed the altered pattern of Aminogram correlating with high L/P ratio and Hyperammonemia, which were positive cases, as confirmed by the clinician who referred. Hence study parameters could be used as preliminary protocol to investigate and screen the IEM.


Inborn errors of metabolism Lactate–pyruvate ratio Amino-acid profile Hyperammonemia Mitochondrial disorder 



Dr. Krishnananda Prabhu RV, Department of Biochemistry Manipal for his critical contributions to the text and Departments of Pediatrics and Neonatology, KMC, Manipal for their clinical referrals. Mrs. Pooja Nayak for data operation.


Vision Group Science and Technology, Centres of Excellence in Science, Engineering and Medicine (CESEM) Karnataka (Grant No. GRD 308/2014-15).

Compliance with Ethical Standards

Conflict of interest

The authors declare that they have no conflict of interest.

Ethical Statement

Ethical clearance approval obtained before the start of the study (IEC 817/2016).

Informed Consent

Informed consents are not applicable. Residual samples after completion of the requested laboratory analysis were anonymized and used for the study. Study results were reported to sample anonymizer who conveyed the reports to the treating clinician.


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Copyright information

© Association of Clinical Biochemists of India 2019

Authors and Affiliations

  1. 1.Department of Biochemistry, Kasturba Medical College, ManipalManipal Academy of Higher EducationManipalIndia
  2. 2.Department of BiochemistryKarwar Institute of Medical SciencesKarwarIndia
  3. 3.Hitech Medicare HospitalUdupiIndia

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