Lysine Disorders - Causes, Symptoms, Effects, and Treatment

Introduction

Lysine is an essential amino acid obtained through diet and supplements. It is the building block of proteins that plays a vital role in maintaining the individual's health. For example, they aid in converting fatty acids to energy and lowering cholesterol levels. And it is a substance critical to maintaining the health of bones and connective tissues of the body.

What Are the Other Names of Lysine?

• Lysine hydrochloride.

• L-Lysine hydrochloride.

• Lysine monohydrochloride.

• Monochlohydrate de lysine.

• Lisina.

• Lys.

What Are the Dietary Sources of Lysine?

Lysine is found in food sources rich in protein, such as,

• Meat, pork, and poultry.

• Eggs.

• Cheese.

• Fish such as cord and sardines.

• Spirulina.

• Fenugreek seeds.

What Are the Forms of Availability of Lysine?

Lysine is available as tablets, creams, capsules, and liquids.

What Are the Benefits of Lysine?

• Protects Against Cold Sores: Cold sores are caused due to herpes simplex virus type 1. The type 1 virus can develop a cold sore when the system gets weakened. But lysine prevents the herpes simplex virus type 1 from replicating by blocking the amino acid arginine, which it needs for replication.

• Reduces Anxiety: Lysine blocks the receptors involved in stress response. It is found helpful to people with schizophrenia as well.

• Improves Absorption and Retention: Lysine increases calcium absorption and prevents calcium excretion through the kidneys. Thus, it protects the bones and is a supplement for osteoporosis.

• Promotes Wound Healing: Lysine becomes active in injury by stimulating collagen production and fastening the repair process. It also encourages the formation of new blood vessels at the site.

• Lysine is found to reduce blood sugar levels.

• It prevents the development of cataracts.

• It can also reduce blood pressure.

What Are the Effects of Intake of Excess Lysine?

The intake of excess lysine can lead to hyperlysinemia. The condition is inherited and shows elevated blood levels of lysine. The condition typically causes no health issues, and the individual affected is unaware of this condition. However, in rare cases, the individual affected presents with behavioral problems and intellectual disability.

What Are the Other Names of Hyperlysinemia?

• Lysine intolerance.

• Lysine alpha-ketoglutarate reductase deficiency.

• Alpha-aminoadipic semialdehyde synthase deficiency.

What Are the Causes of Hyperlysinemia?

Hyperlysinemia is an autosomal recessive condition caused by a mutation in the aminoadipic semialdehyde synthase gene.

What Is AASS?

The AASS (alpha-aminoadipic semialdehyde synthase) gene provides the information for making the enzyme aminoadipic semialdehyde synthase. It helps in the breakdown of lysine. Initially, the enzyme breaks down lysine into saccharopine. Then the saccharopine molecule breaks down into alpha-aminoadipate semialdehyde.

When Do the Symptoms of Hyperlysinemia Begin and What Are Those?

The symptoms can occur in the following age groups.

• Prenatal.

• Newborn.

• Infant.

• Child.

• Adolescent.

• Adult.

• Older adult.

The symptoms of hyperlysinemia are:

• Abnormality in behavior.

• Delay in speech and language development.

• Muscular hypotonia in infants.

• Intellectual disability with an IQ (intellectual quotient) score below 70.

• Microcephaly.

• Seizures.

• Short stature.

• Abnormality in face shape.

• Abnormality of movement.

• Lack of physical coordination.

• Premature closure of cranial sutures.

• Depressed nose.

• Difficulty in swallowing.

• Impaired ability to eat.

• Gastroesophageal reflux.

• Hyperactivity.

• Hypotelorism - closely spaced eyes.

• Poor motor coordination.

• Misalignment of eyes.

• Tremors.

• Vomiting.

How to Diagnose Hyperlysinemia?

To diagnose, an initial medical history assessment and physical examination are necessary. In addition, the past and present history of illnesses are recorded. The history of allergies is also assessed. Finally, the history of medications taken or treatments undergone is recorded.

The process of physical examination involves:

• Check vital signs such as temperature, heart rate, breathing rate, weight, height, and blood pressure.

• Checking the person’s body for any signs of pain, tenderness, and swelling.

• Evaluating the nervous system by checking the reflexes, sensory and motor function, and coordination.

Newborn Screening: A series of tests are performed on newborns for at least 30 genetic diseases assessing the heart and other sensory impairments. Further testing is done to confirm the diagnosis if any tests are positive.

Genetic Tests: The test is conducted to report the genetic changes as pathogenic, benign, and unknown variants. Once the test is done, the doctor will explain the result and discuss the following process.

Laboratory Tests: The individual’s blood, urine, and body tissues are checked. The tests conducted depend on the symptoms that the individual experiences. For example, the laboratory findings of hyperlysinemia show elevated levels of lysine.

Imaging Tests: The tests are based on the identified symptoms and provisional diagnosis.

What Does It Mean if Plasma Lysine Level Is Too High?

If plasma levels of lysine are high, it indicates an increased intake of lysine supplements or decreased lysine metabolism. So, adding vitamin C, niacin, vitamin B6, alpha-ketoglutarate, and iron improves lysine utilization.

What Is the Treatment for Hyperlysinemia?

The treatment approach for a genetic and rare disease is often the management of symptoms. Treatment planning is improved by building a medical team with specialized professionals. The team comprises specialists based on the symptoms the patient experiences. The need for a different specialist may change over time. The primary healthcare provider focuses on the overall health of the patient. A genetic counselor is one on the team. They have received training in medical genetics and counseling. They discuss the history, risks, tests, and treatment options with the individual and family.

The symptoms are treated with medications, diet management, speech therapy, and supportive care. The symptom management is continued until there is a confirmatory diagnosis.

What Happens During Lysine Deficiency?

Individuals with lysine deficiency experience the following symptoms.

• Nausea.

• Dizziness.

• Loss of appetite.

• Agitation.

• Fatigue.

• Anemia.

• Bloodshot eyes.

• Reproductive disorders.

Conclusion

The rare diseases may be rare individually, but they may be found to affect millions of people. Individuals and their families may face challenges due to these rare diseases. The best approach to treatment is to manage the symptoms and work together towards improving life.