Pearson's syndrome is a very rare genetic disease that occurs in infancy and in most cases leads to an early death.
Discovery story
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 due to long-term follow-up of four children with similar symptoms: they had sideroblastic anemia, which did not respond to standard treatment, insufficiency of exocrine pancreatic function and bone marrow cell pathology.
At first, the children were given a different diagnosis - Schwahman's syndrome (congenital pancreatic hypoplasia). But after examining the blood and bone marrow, obvious differences were revealed, which gave reason to separate Pearson's syndrome into a separate category.
Causes of the disease
The study of the causes of the disease took about ten years. Geneticists were able to find a genetic defect that leads to the division and duplication of mitochondrial DNA.
Although the disease is genetic, the mutation usually appears spontaneously, and a sick baby is born to completely healthy 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, iron accumulates in the liver, sclerosis of the glomeruli of the kidneys, and the formation of cysts. In some cases, myocardial fibrosis develops, which leads to heart failure.
The pancreas secretes an insufficient amount of lipase, amylase and bicarbonate in all patients with Pearson's disease. The syndrome is manifested by atrophy of the gland tissue and its subsequent fibrosis.
Diagnostic Methods
Only geneticists can make a diagnosis with confidence after examining mitochondrial DNA. A regular 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 "Cyanocobalamin" and iron preparations.
Thanks to bone marrow puncture, a decrease in the total number of cells, the presence of vacuoles in erythroblasts, and the appearance of ring-shaped sideroblasts can be seen.
Symptoms of the disease
From the first days of a child's life, Pearson's syndrome can be suspected. Symptoms of the disease debut in infants in the form of pernicious anemia and insulin-dependent diabetes mellitus. Pale skin, drowsiness, lethargy, diarrhea, periodic vomiting are observed, the child is gaining weight poorly. Food is almost not absorbed, steatorrhea is characteristic. Symptoms of diabetes mellitus occur, blood glucose levels increase, and a tendency to acidosis appears. Perhaps the development of hepatic, renal and heart failure.
Sometimes, in addition to anemia, pancytopenia occurs (deficiency of not only red blood cells, but also platelets and white blood cells), which will manifest itself as a tendency to bleeding and frequent infection.
Treatment and prognosis
Unfortunately, doctors still do not know how to overcome Pearson's syndrome. Its treatment is nonspecific and gives only short-term results.
Anemia is not amenable to standard therapy and requires frequent blood transfusions. Enzymes are prescribed to improve pancreatic function, and infusion therapy is prescribed to correct metabolic disorders. In rare cases, bone marrow transplantation is performed.
Pearson's syndrome has an unfavorable prognosis: children are behind in physical development, most die before two years of age. In isolated cases, patients live longer thanks to effective supportive care, but at an older age the disease leads to muscle atrophy, characteristic of Kearns-Sayre syndrome.
The severity of the course of the disease largely depends on the degree of DNA damage.