Lysinuric Protein Intolerance

Alternative Names

  • LPI
  • Dibasic Amino Aciduria II
Back to search Result
WHO-ICD-10 version:2010

Endocrine, nutritional and metabolic diseases

Metabolic disorders

OMIM Number


Mode of Inheritance

Autosomal recessive

Gene Map Locus



Lysinuric protein intolerance (LPI) is a very rare multisystem disease caused by abnormalities in the metabolism of the amino acids lysine, arginine, and ornithine. Patients with LPI have features associated with protein intolerance, bone marrow abnormalities, altered immune response, osteopenia, intellectual disability, chronic renal disease, and lung involvement. Diagnosis is based on the concentration of lysine, arginine, and ornithine in plasma and urine; increased urinary excretion and low plasma concentrations indicate a positive diagnosis for LPI.

Mutations in the SLC7A7 gene have been identified in patients with LPI. SLC7A7 gene encodes the lighter protein subunit of a sodium-independent cationic amino acid transporter, which is involved in the transport of certain amino acids between cells. Mutations in SLC7A7 gene impair the transport of lysine, arginine, and ornithine amino acids, and increase the excretion of these amino acids through urine.

Epidemiology in the Arab World

View Map
Subject IDCountrySexFamily HistoryParental ConsanguinityHPO TermsVariantZygosityMode of InheritanceReferenceRemarks
222700.1MoroccoFemale Renal Fanconi syndrome; Metabolic acido...NM_003982.4:c.726G>AHomozygousAutosomal, RecessiveBenninga et al. 2007
222700.2.1TunisiaMaleYesYes Small for gestational age; Hyperammone...NM_003982.4:c.1185_1188delHomozygousAutosomal, RecessiveSperandeo et al. 2000
222700.2.2TunisiaMaleYesYes Hyperammonemia; Elevated sweat chlorideNM_003982.4:c.1185_1188delHomozygousAutosomal, RecessiveSperandeo et al. 2000 Brother of 222700.2....
222700.3.1TunisiaFemaleYesYes Abnormal macrophage count; Abnormal lym...NM_003982.4:c.1185_1188delHomozygousAutosomal, RecessiveEsseghir et al. 2011 Proband and sibling ...
222700.3.2TunisiaUnknownYesYesNM_003982.4:c.1185_1188delHomozygousAutosomal, RecessiveEsseghir et al. 2011 Lysinuric protein in...
222700.4United Arab EmiratesUnknown HyperammonemiaNM_003982.4:c.499+1G>CHomozygousAutosomal, RecessiveBen-Rebeh et al. 2012
222700.5JordanUnknown HyperammonemiaNM_003982.4:c.1034C>GHomozygousAutosomal, RecessiveBen-Rebeh et al. 2012
222700.G.1United Arab EmiratesUnknown HyperammonemiaNM_003982.4:c.499+1G>C, NM_003982.4:c.999G>C, NM_003982.4:c.1005C>AHomozygousAutosomal, RecessiveAl-Shamsi et al. 2014 Mutations reported i...

Other Reports


Lauteala et al. (1998) used linkage and haplotype analysis to study the possibility of genetic heterogeneity in LPI. Their study sample of 19 affected non-Finnish families included one Saudi Arabian and two Moroccan families. The condition was diagnosed in the index patients based on a clinical evaluation and laboratory results, including increased urinary excretion, low plasma concentrations of lysine, arginine, and ornithine, and hyperammonemia and/or oroticaciduria after nitrogen load. Two-point linkage analysis in all families gave positive lod scores on the proximal long arm of chromosome 14. These results were similar to that previously observed with Finnish patients, suggesting genetic homogeneity in LPI.

Saudi Arabia

[See: Morocco > Lauteala et al., 1998].

United Arab Emirates

Al-Shamsi et al. (2014) undertook a study to calculate the birth prevalence of IEMs among Emiratis in the UAE by taking into consideration all neonates born with an inherited metabolic condition at Tawam Hospital between 1995 and 2012. A total of 37 distinct IEMs were found in Emirati neonates in this study, providing an estimated IEM birth prevalence of 75.24 per 100,000 live births. Lysinuric Protein intolerance was found to have a birth prevalence of less than 0.98 per 100,000.

© CAGS 2022. All rights reserved.