Reduced serum copper oxidase absorbance is an important manifestation of mental disorders associated with hepatomegaly. Autosomal recessive monogenic disorders have a positive family history in about 20-30% of cases most of which develop in the sibling generation. The presence of at least 25 mutations in the gene, located on chromosome 13, has not been determined as to whether the defect is a structural or control gene. The pathological changes are mainly in the nucleus accumbens, but the cerebral cortex can also be damaged and pathological sections show degeneration or loss of neuronal cells in the nucleus accumbens and caudate nucleus, which are replaced by astrocytes. If copper is deposited in large amounts in the liver, hepatomegaly, acute or chronic hepatitis and cirrhosis, and liver atrophy may occur. What causes a decrease in serum copper oxidase absorbance? Autosomal recessive monogenic disorders have a positive family history in about 20% to 30% of cases, most of which develop in the sibling generation. At least 25 mutations have been found in the gene, which is located on chromosome 13. Whether the defect is a structural or control gene has not been determined. The lack of plasma copper cyanobactin in patients who cannot bind copper results in large amounts of copper deposited in the liver and brain (nucleus accumbens), cornea and kidneys, leading to impaired copper metabolism and causing a series of functional and histological damage to the internal organs; the most common sites are the basal nucleus, cerebellum, cerebral cortex, cornea, liver and kidneys. Pathological changes are mainly in the nucleus accumbens, and the cerebral cortex can also be damaged. Pathological sections show degeneration or loss of neuronal cells in the nucleus accumbens and caudate nucleus, which are replaced by astrocytes. If copper is deposited in the liver, hepatomegaly, acute or chronic hepatitis, cirrhosis and hepatic atrophy may occur. The majority of the disease has a slow onset, with initial extrapyramidal symptoms, such as limb tremors, oscillations, increased muscle tone, and involuntary movements. About 20% of the patients have psychiatric disorders as their first symptoms, and most of the pediatric patients have psychiatric abnormalities as their first symptoms, which manifest as abnormal mood or decreased learning ability.