lysinuric protein intolerance

Lysinuric protein intolerance (LPI) is a rare genetic disorder that affects the body's ability to digest and use certain amino acids, specifically lysine, arginine, and ornithine [2]. This condition leads to various metabolic complications and is characterized by the body's inability to properly digest and use proteins [5].

The symptoms of LPI can vary widely among individuals but often include:

• Nausea and vomiting after consuming protein-rich foods
• Abdominal pain and diarrhea
• Failure to thrive (in children)
• Hepatosplenomegaly (enlargement of the liver and spleen)
• Renal hyperdiaminoaciduria (excessive urinary excretion of dibasic amino acids)

LPI is an autosomal recessive disorder, meaning that a person must inherit two copies of the mutated gene (one from each parent) to develop the condition [7]. The disease is characterized by protein-rich food intolerance with secondary urea cycle disorder, but symptoms are heterogeneous ranging from mild to severe [9].

In summary, LPI is a rare genetic disorder that affects the body's ability to digest and use certain amino acids, leading to various metabolic complications and symptoms such as nausea, vomiting, abdominal pain, and failure to thrive.

Lysinuric protein intolerance (LPI) is a rare genetic disorder that affects the body's ability to properly digest and use certain proteins. The signs and symptoms of LPI can vary from person to person, but here are some common features:

• Enlarged liver and spleen: People with LPI often have an enlarged liver and spleen (hepatosplenomegaly), which can lead to discomfort and pain in the upper right abdomen.
• Short stature: Individuals with LPI may experience short stature, which is a result of impaired growth and development due to protein malabsorption.
• Muscle weakness: Muscle weakness is another common symptom of LPI, which can make everyday activities more challenging.
• Nausea and vomiting: People with LPI often experience nausea and vomiting after consuming high-protein foods, which can lead to dehydration and electrolyte imbalances.
• Impaired immune function: The impaired protein digestion in LPI can weaken the immune system, making individuals more susceptible to infections.
• Failure to thrive: Children with LPI may experience failure to thrive, which is a condition characterized by slow growth and development.

These symptoms can be caused by the body's inability to properly digest and use certain proteins, leading to various metabolic complications. It's essential for individuals with suspected LPI to seek medical attention from a qualified healthcare professional for proper diagnosis and treatment.

References:

• [1] Mar 10, 2023 — People with lysinuric protein intolerance have a variety of features, such as an enlarged liver and spleen (hepatosplenomegaly), short stature, ...
• [3] What are the signs and symptoms? · Nausea · Vomiting · Enlarged spleen · Enlarged liver · Impaired immune function · Increased susceptibility to developing ...
• [6] People with lysinuric protein intolerance have a variety of features, such as an enlarged liver and spleen (hepatosplenomegaly), short stature, muscle weakness, ...
• [7] Symptoms include failure to thrive, hepatosplenomegaly, and a range of clinical manifestations affecting various organs. Patients may experience vomiting, ...

Lysinuric protein intolerance (LPI) can be accurately diagnosed through various diagnostic tests, which are essential for confirming the condition.

• Genetic testing: This is a crucial test for diagnosing LPI. It involves analyzing the SLC7A7 gene to identify any mutations that may be causing the condition [6]. Genetic testing can confirm whether an individual has inherited two copies of the mutated gene (one from each parent), which is necessary for developing LPI [4].
• Laboratory findings: Laboratory tests, such as blood ammonia levels, can help diagnose LPI. Elevated blood ammonia levels after meals may indicate transient hyperammonemia, a condition that can lead to the diagnosis of LPI [5].
• Single-gene testing: This test is another approach for diagnosing LPI and involves analyzing the SLC7A7 gene specifically [1].

These diagnostic tests are essential for confirming the diagnosis of lysinuric protein intolerance. They help identify the genetic mutations responsible for the condition, which is crucial for developing a treatment plan.

References: [1] Dec 21, 2006 — When the phenotypic and laboratory findings suggest the diagnosis of LPI, molecular genetic testing approaches can include single-gene testing ... [4] by A Olgac · 2020 · Cited by 4 — Lysinuric protein intolerance (LPI) is an autosomal recessively inherited inborn error of metabolism (IEM) caused by the defect in the dibasic ... [5] by A Noguchi · 2019 · Cited by 46 — In some cases, transient hyperammonemia is detected by examining blood ammonia only after meals, which may lead to diagnosis of this disease. [6] The SLC7A7 gene is associated with autosomal recessive lysinuric protein intolerance (LPI) (MedGen UID: 75704) ... Diagnostic testing of this gene is recommended ...

Treatment Options for Lysinuric Protein Intolerance

Lysinuric protein intolerance (LPI) is a rare genetic disorder that affects the body's ability to digest and use certain amino acids. The treatment options for LPI are focused on managing symptoms and preventing complications.

• Nitrogen-scavenger drugs: These medications, such as sodium benzoate and phenylacetate, help remove excess ammonia from the blood, which is a common complication of LPI [1].
• Dextrose infusion: Administering dextrose (glucose) intravenously can help lower blood ammonia levels by promoting the excretion of nitrogenous waste products [2].
• Extra-renal depuration: This treatment involves using medications to remove excess nitrogen from the body, which is particularly important in acute hyperammonemic crises [1].

Oral Supplements

In addition to these treatments, oral supplements are also used to manage LPI. These include:

• Arginine and citrulline: Supplementing with these amino acids can help alleviate symptoms of LPI by providing the body with essential nutrients that it cannot produce on its own [3].
• Citrulline supplementation: This is a common treatment for LPI, as citrulline is a neutral amino acid that can be absorbed normally in patients with this disorder [4][5].

Protein-Restricted Diet

A protein-restricted diet is also an essential part of managing LPI. This involves limiting the intake of protein-rich foods to prevent excessive nitrogen buildup in the body [6][7].

Lysinuric protein intolerance (LPI) can be included in the differential diagnosis of malabsorptive diseases, particularly those that present with symptoms such as failure to thrive and chronic digestive issues [1][5].

The differential diagnosis for LPI may include conditions such as:

• Celiac disease: This is a common condition that affects the small intestine and leads to malabsorption of nutrients. However, unlike LPI, celiac disease is typically diagnosed in childhood or adolescence, and symptoms often improve with a gluten-free diet [1].
• Hemophagocytic lymphohistiocytosis/macrophagic activation syndrome: This is a rare condition characterized by an overactive immune response that can lead to inflammation and damage to various organs. While it shares some similarities with LPI, such as hepatosplenomegaly and short stature, the two conditions have distinct underlying mechanisms [1].
• Other malabsorptive diseases: Conditions like pancreatic insufficiency, intestinal obstruction, or other rare genetic disorders may also be considered in the differential diagnosis of LPI.

A detailed patient history, physical examination, and laboratory testing are essential for diagnosing LPI. The condition is often complicated by various metabolic complications, such as hyperferritinemia, hypercholesterolemia, and acute pancreatitis [6].

It's worth noting that LPI can be diagnosed in infancy or early childhood, making it crucial to consider this condition in the differential diagnosis of malabsorptive diseases in young children.

References: [1] Mar 10, 2023 — People with lysinuric protein intolerance have a variety of features, such as an enlarged liver and spleen (hepatosplenomegaly), short stature, ... [5] by W Mauhin · 2017 · Cited by 102 — LPI is often revealed by the appearance of chronic digestive symptoms and failure to thrive after presumptive diagnoses of coeliac disease, ... [6] by I Kalay · 2023 · Cited by 1 — Hyperferritinemia, hypercholesterolemia, hypertriglyceridemia, and acute pancreatitis might also be observed [1]. The diagnosis of LPI is often complicated due ...