Observational Study
Copyright ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Pediatr. Jul 9, 2022; 11(4): 369-374
Published online Jul 9, 2022. doi: 10.5409/wjcp.v11.i4.369
Children with lysinuric protein intolerance: Experience from a lower middle income country
Syed Bilal Hashmi, Sibtain Ahmed
Syed Bilal Hashmi, Sibtain Ahmed, Department of Pathology and Laboratory Medicine, Aga Khan University Hospital, Karachi 74800, Pakistan
Author contributions: Ahmed S designed and conceived the idea, assisted in the write-up of the first draft and critically reviewed the manuscript; Hashmi SB performed the data collection, literature review and the majority of the write-up in the first draft.
Institutional review board statement: Study commenced after approval was obtained from the institutional ethics committee (No. 2018-0553-894).
Conflict-of-interest statement: No conflict-of-interest to declare.
Data sharing statement: Dataset available from the corresponding author at ude.uka@demha.niatbis. Consent was not obtained as the presented data are anonymized and risk of identification is low.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Sibtain Ahmed, FCPS, MBBS, Assistant Professor, Department of Pathology and Laboratory Medicine, Aga Khan University Hospital, National Stadium Rd, Karachi 74800, Pakistan. sibtain.ahmed@aku.edu
Received: December 29, 2021
Peer-review started: December 29, 2021
First decision: March 16, 2022
Revised: March 21, 2022
Accepted: June 3, 2022
Article in press: June 3, 2022
Published online: July 9, 2022

Lysinuric protein intolerance (LPI) is an inborn error of metabolism consequential to recessive mutations in the SLC7A7 gene. The metabolic imbalance in absorption and excretion of dibasic amino acids is considered the basis of LPI. The disease results from protein intolerance with signs and symptoms oscillating from cerebral impairment, respiratory involvement, renal failure and autoimmune complications.


To determine biochemical and clinical presentation of cases with biochemical picture suggestive of LPI in Pakistani children.


The study was conducted at the Biochemical Genetic Lab, Department of Pathology and Laboratory Medicine, AKU Plasma, and urine amino acid quantification data from January 2013 to October 2018 was included in this study. The amino acids were analyzed by high performance liquid chromatography. Prestructured requisition forms were used to obtain the clinicopathological data. Statistical analysis was done by Microsoft Excel 2017.


A total of 6 patients were recognized. All the patients were male (100%). The mean age was 24 mo ± 10 d. All the patients had low plasma concentration of lysine, ornithine and arginine, whereas increased levels of lysine, ornithine and arginine in urine were observed in 2 patients. History of consanguineous marriage was present in all patients (100%). The most observed clinical symptom was feeding difficulty followed by failure to thrive (83.3%) and developmental delay (66.6%). Hepatomegaly was present in all patients (100%). No mutation analysis was done.


This study portrays the biochemical and clinical spectrum of LPI in Pakistan. Although clinical manifestations appeared in the first 2 years of life, most of them suffered a delay in undergoing diagnostic workup.

Keywords: Lysinuric protein intolerance, Consanguinity, Pakistan, Retrospective study

Core Tip: Lysinuric protein intolerance is an inherited biochemical disorder with just over 140 individuals worldwide. In this disorder, there is defective absorption and excretion of dibasic amino acids, such as lysine, arginine and ornithine. This is the first study from Pakistan, which has a high prevalence of inherited metabolic disorders. Only 4 previously reported cases were identified from South Asia. This study shows the biochemical pattern and clinical characteristics in patients with a suggestive diagnosis of lysinuric protein intolerance on biochemical workup.