Aetiology
Disorders of lysine or hydroxylysine metabolism are caused by autosomal recessive mutations in the genes that code for enzymes involved in lysine and hydroxylysine metabolism. These mutations lead to an inability of the body to break down lysine or hydroxylysine, causing a buildup of these amino acids in the body.
Diagnosis
Disorders of lysine or hydroxylysine metabolism are usually diagnosed through a combination of clinical evaluation, biochemical testing and genetic testing. Clinical evaluation may include looking at the patient’s medical history, physical exam, and any symptoms the patient is experiencing. Biochemical testing can be used to measure the levels of lysine and hydroxylysine in the blood and urine. Genetic testing is used to identify the specific mutation that is causing the disorder.
Differential diagnosis
Differential diagnosis of disorders of lysine or hydroxylysine metabolism include other inborn errors of metabolism, as well as conditions that can cause a similar build-up of lysine or hydroxylysine in the body such as kidney or liver disease.
Treatment
Treatment for disorders of lysine or hydroxylysine metabolism can include dietary modification, supplementation of the deficient enzymes, and medications such as diuretics or anti-inflammatories.
Prognosis
The prognosis for disorders of lysine or hydroxylysine metabolism depends on the severity of the mutation and the effectiveness of the treatment. With proper treatment, prognosis is generally good.