Pearson's syndrome is a very rare genetic disease that manifests itself in infancy and in most cases leads to early death.
Discovery history
Another name for Pearson's syndrome is congenital sideroblastic anemia with exocrine pancreatic insufficiency. The disease is named after the scientist who first described it in 1979 - N. A. Pearson. The syndrome was recognized through long-term follow-up of four children with similar symptoms: they had sideroblastic anemia that did not respond to standard treatment, exocrine pancreatic insufficiency, and pathology of bone marrow cells.
At first, the children were given a different diagnosis - Shwachman's syndrome (congenital hypoplasia of the pancreas). But after a study of blood and bone marrow, clear differences were revealed, which gave rise to Pearson's syndrome in a separate category.
Causes of disease
The study of the causes of the disease took about ten years. Geneticists have managed to find a genetic defect that leads to the division and duplication of mitochondrial DNA.
Although the disease is genetic, usually the mutation appears spontaneously, and the sick baby is born in absolutelyhe althy parents. Sometimes there is a relationship between the presence of ophthalmopathy in the mother and the development of Pearson's syndrome in her child.
DNA defects can be detected in the bone marrow, pancreatic acinocytes, as well as in organs that are not the main targets of the disease - kidneys, heart muscle, hepatocytes. On the other hand, in some patients, in the presence of a typical clinical and laboratory picture, it is not possible to register changes in mitochondrial DNA.
In sick children, there is an accumulation of iron in the liver, sclerosis of the glomeruli of the kidneys, and the formation of cysts. In some cases, myocardial fibrosis develops, leading to heart failure.
The pancreas secretes insufficient amounts of lipase, amylase and bicarbonates in all patients with Pearson's disease. The syndrome is manifested by atrophy of the gland tissue and its subsequent fibrosis.
Diagnostic Methods
With confidence, only geneticists can make a diagnosis after examining mitochondrial DNA. A routine peripheral blood test also plays an important role: severe macrocytic anemia, neutropenia, and thrombocytopenia are detected. Notable is the lack of effect from the treatment of anemia with "Cyancobalamin" and iron preparations.
Due to a bone marrow puncture, a decrease in the total number of cells, the presence of vacuoles in erythroblasts and the appearance of annular sideroblasts can be seen.
Disease symptoms
From the first days of a child's lifePearson's syndrome may be suspected. Symptoms of the disease debut in infants in the form of pernicious anemia and insulin-dependent diabetes mellitus. Pallor of the skin, drowsiness, lethargy, diarrhea, periodic vomiting are observed, the child gains weight poorly. Food is almost not digested, steatorrhea is characteristic. Symptoms of diabetes mellitus occur, the level of glucose in the blood rises, and there is a tendency to acidosis. Possible development of liver, kidney and heart failure.
Sometimes, in addition to anemia, pancytopenia occurs (a deficiency of not only erythrocytes, but also platelets and leukocytes), which will manifest itself as a tendency to bleeding and frequent infections.
Treatment and prognosis
Unfortunately, doctors still do not know how to beat Pearson's syndrome. Its treatment is non-specific and gives only short-term results.
Anemia does not respond to standard therapy and requires frequent blood transfusions. To improve the function of the pancreas, enzymes are prescribed, and infusion therapy is prescribed to correct metabolic disorders. In rare cases, a bone marrow transplant is performed.
Pearson's syndrome has an unfavorable prognosis: children lag behind in physical development, most die before the age of two. In isolated cases, patients live longer thanks to effective maintenance therapy, but at an older age, the disease leads to muscle atrophy, characteristic of Kearns-Sayre syndrome.
Severity of the course of the disease duringlargely depends on the degree of DNA damage.
