Contrary to what we could think, diseases classified as “ rare ” are manifested in a high number of the population but there is a lack of knowledge about their existence, which causes disorientation in the diagnosis and late or inexisting treatments , affecting directly the life quality of the patients.
According to the European Commission , the definition of “rare diseases” refers to the conditions whose prevalence index is under five per every 10,000 people . Until now, over 6,000 diseases of this kind have been identified, which is equivalent to nearly 300 million people who have them around the world. 90% of them have a genetic origin and 70 % of them affect children .
The International Day of Rare Diseases was established on February 29, 2008 ; this day was chosen for being an unusual day, for usually, February only has 28 days except for every four years when leap year takes place).
The incidence of rare pathologies in Mexico is of nearly 8 million people although, according to experts, there are no exact numbers on the impact they have in our country.
During a conference on rare diseases , neurologist Daniela Morales expressed that currently, there are still no medical needs covered: “How long does a patient with this kind of disease live? It is known that over half of these diseases begin in childhood and, from the third part of those patients does not live longer than five years without treatment, which shows the impact these diseases can have on the life quality of the patient.”
Recommended: UNAM students design toys for cerebral palsy rehabilitation
The expert said that late diagnosis is linked to the low prevalence of the diseases and confusion with the symptoms : “From five to seven years after the presence of the first symptom can go through without the disease being diagnosed and patients can visit up to eight doctors before finding the real diagnosis ,” she added.
Only 5% of rare diseases have available treatments . Regarding associations, only half of the diseases are within a group of specific supports, such as the Mexican Federation of Rare Diseases (Femexer), that fights against Gaucher disease since 1990 . Generally, several diseases unite in a single association.
These diseases are classified by the way they are transmitted: genetic , autoimmune , post-infectious , and lysosomal .
Diseases from the lysosomal group are caused by a genetic mutation that provokes an alteration of the cell enzyme and affects several organs at the same time.
The lysosome inside our organism is in charge of digesting what cells do not need, those wastes must be crushed by enzymes in small cuts so as to expel them. When a person has a mutation affecting their DNA , the enzyme does not have an adequate structure and cannot properly cut the unnecessary waste in the cell. Hence, they accumulate inside the lysosome.
Currently, diseases from the lysosomal group are the only ones with available treatment . Among them are the Gaucher disease , the Hunter syndrome , the Fabry disease , and Hereditary angioedema ; together, they have an incidence of 7,000 newborns .
Gaucher disease
Identified in 1882 by the French doctor Ernest Gaucher , it lacks the glucocerebrosidase enzyme . One in every 855 persons has it and it is one of the most frequent. It generates an accumulation of fat in different areas of the body such as the liver , bone , and bone marrow : it also causes anemia and low white-cells counts. There are three kinds but 90% of patients have type 1, which increases the size of internal organs.
Hunter syndrome
Discovered in 1917 , it is a rare condition that lacks the iduronate-2-sulfatase enzyme . It manifests in the abnormal growth of internal organs like the liver and heart ; in addition, the patient presents facials particularities such as the increase of the size of the head, thick lips, wide nose, and swollen eyes and it causes intellectual disability .
“Although females are the carriers, for its localization in the X chromosome , they don’t present visible symptoms and it only manifests in one of 162 thousand men ,” added the expert.
Recommended: The fatal results of the 1918 Spanish flu pandemic in Mexico
For early diagnosis , doctors can look for the presence of umbilical hernias and frequent problems in the respiratory tract as well as spots in the lower back. These symptoms can be present in other diseases, so the connection of the symptoms is the main key.
Fabry disease
Doctor Morales
explained that this disease is transmitted by the X chromosome and it causes the lack of the alfa-galactosidase A enzyme with the accumulation of Gb3 . It affects the function of the heart , brain , and kidneys . It affects one in every 40,000 to 117,000 persons .
In males , the disease appears from 9 years old but is diagnosed until 23 years of age , while in women , it appears at 13 years old and is detected until 32 years of age .
Some of the symptoms are the lack of sweating, gray or golden lines in the cornea, red spots, and burning pain in hands and feet.
Hereditary angioedema
Known as a genetic condition , it produces recurrent painful swelling episodes in the abdomen, face, feet, genitals, hands, and throat, causing deformity and incapacity, with a prevalence of one in every 50,000 people . According to the Hereditary Angioedema Association , there must be 2,740 patients in Mexico. This is a genetic defect in the protein that regulates the system. 20% to 25% of patients do not have family antecedents with their mutation appearing spontaneously.
The treatment to fight this kind of disease is known as “ enzyme replacement therapy ” and is related to the obtention of a healthy person’s DNA through a reading of their genetic material so as to replicate and produce the same kind of enzyme through genetic engineering .
The expert in genetic diseases, Daniela Morales, insisted that there is an urgent need for medical innovation , as well as training so that experts are informed about the existence of these diseases and also to supply the means for their treatment .
Recommended: UNAM scientists develop tuberculosis antibiotic from scorpion venom
mp