Pearson’s syndrome: what it is, symptoms, causes and treatment.

This rare genetic disease mainly affects the pancreas and blood.

Pearson's syndrome is a rare medical condition that, despite only less than a hundred known cases worldwide, has aroused the interest of geneticists and molecular biologists since its discovery in the 1970s.

In this article we will take a closer look at this rare disease, learning about its symptoms, causes, diagnosis and treatment.

What is Pearson's syndrome?

Pearson's syndrome is a disease of genetic origin, caused by alterations in the DNA found inside the mitochondria.. This alteration is due in most cases to mutations that occur during cell division when the embryo is being formed.

Being a disease caused by something that is found inside each of the cells of the organism, there is no known way to cure it, in addition to presenting a very poor prognosis, with individuals diagnosed with Pearson being children who will rarely live more than three years.

There are several problems derived from this rare medical condition, the main ones being hematological, hepatic and muscular. All this leads to a limited ability of the individual to interact with the world around him, in addition to presenting problems in growth.

The first person to describe it was the person after whom it is named, Howard Pearson, in 1979. This disease is so rare that, to date, only about seventy cases have been reported in the international literature..

Causes

Pearson's syndrome is genetic in origin. It occurs as a result of an alteration in the DNA inside the mitochondrion, the organelle responsible for cellular respiration. This alteration may be due either to a deletion, i.e. the partial or total loss of the DNA molecule, or to duplication, i.e. a region of the DNA is replicated. These alterations are due, in most cases, to mutations in the genetic material of the individual.

These alterations cause the metabolism to be affected, causing the cell not to receive energy in the correct way.This ultimately affects basic and vital processes for the organism, such as the active transport of substances in the cell, muscle contraction, synthesis of molecules, among others.

Diagnosis

The clinical presentation of Pearson's syndrome is variable, which makes it necessary to follow the patient closely to confirm that he/she has the condition, as well as to find out what are the main problems suffered by the individual in question, since as with any other disease, the symptomatology from patient to patient may be different. The main diagnostic tool for this syndrome is a biochemical-molecular studyin which it will be seen whether or not there is an alteration in the mitochondrial DNA.

In most cases, genetic analysis can only be done once the baby is born and the first symptoms possibly associated with Pearson's syndrome are detected in the specific case. Although prenatal testing for the syndrome is theoretically possible, analyzing and interpreting the results is difficult and risky for the life of the developing fetus.

Symptoms

The first symptoms of the syndrome appear during the first year of life, some of the most striking being blood and pancreatic problems are among the most striking.. In most cases, individuals do not live more than three years.

In this syndrome there are problems in the bone marrow, which implies problems at the Blood level. The marrow does not produce white blood cells (neutrophils) efficiently (pancytopenia), which causes the individual to develop anemia, which can evolve very seriously. It also presents low platelet count and aplastic anemia.

In relation to the pancreas, specifically to the exocrine part of the pancreas (exocrine pancreatic insufficiency), in this syndrome there is a dysfunction in this organ, causing a greater atrophy of the organ.

Because of this, individuals who suffer from Pearson's syndrome have problems absorbing nutrients from food, which leads to nutritional problems.This leads to nutritional problems that present themselves in growth problems and difficulty gaining weight, as well as frequent diarrhea.

But in addition to problems in the blood and pancreas there are many other symptoms that define this disorder, which is considered a multisystemic mitochondrial disease. Some of these symptoms are:

• Refractory sideroblastic anemia.
• Defective oxidative phosphorylation.
• Renal and endocrine failure.
• Hepatic insufficiency.
• Neuromuscular disorders and myopathies.
• Cardiac problems.
• Atrophy of the spleen.

Treatment

Pearson's syndrome, as we have already seen, is of genetic origin, since it consists of an alteration of the mitochondrial DNA. This, with the therapeutic tools that current medicine has, it is not possible to solve it and, therefore, this syndrome has no known cure.

However, this does not mean that a treatment cannot be applied to the person who has this medical condition. While the therapy is focused on palliating the therapy is focused on alleviating the symptomatologyAlthough therapy is focused on palliating the symptoms, with little chance of bringing about a significant change in their manifestation, it is an ideal treatment for improving the patient's quality of life, as well as reducing or directly preventing the appearance of other problems that may be secondary to Pearson's syndrome, such as infections.

Among the problems associated with the syndrome is Earns-Sayre syndrome.which involves deterioration of the retina, hearing loss, diabetes and cardiovascular disease. Other problems are sepsis, endocrine disorders, lactic acidosis production crisis and liver failure. All these pathologies are what contribute, combined with the syndrome, to the fact that children with this diagnosis do not have a life expectancy of much more than three years.

Those individuals who survive early infancy progressively show hematologic signs that resolve spontaneously, while neurologic and muscular problems emerge and worsen. If they have not presented Kearns-Sayre syndrome before, the children will probably present it after they have passed the age of three years.

It should be noted that there is there is a surgical intervention that can significantly improve the patient's life, although its purpose is palliative.. This is a bone marrow transplant, since the syndrome affects the marrow in a very marked way and this type of intervention allows the patient's life to be stretched a little further. If this option is not possible, blood transfusions are very frequent, especially to avoid severe anemia associated with erythropoietin therapy.

Bibliographic references:

• Cammarata-Scalisi, Francisco & López-Gallardo, Ester & Emperador, Sonia & Ruiz-Pesini, Eduardo & Silva, Gloria & Camacho, Nolis & Montoya, Julio. (2011). Pearson's syndrome: A case report. Clinical Research. 52. 261-267.
• Pearson HA, Lobel JS, Kocoshis SA, Naiman JL, Windmiller J, Lammi AT, Hoffman R, Marsh JC. (1979) A new syndrome of refractory sideroblastic anemia with vacuolization of marrow precursors and exocrine pancreatic dysfunction. J Pediatr 1979; 95:976-984.