AThe mutations in the gene that cause Sjögren-Larsson syndrome – genetic dermatosis with neurological changes – received special attention from dermatologist Mariam Patrícia Auada Souto in her doctoral work carried out at the Faculty of Medical Sciences (FCM). The disease, although rare, appeared in Brazil 40 years ago and its highest prevalence can be observed in Sweden, where the first occurrences were recorded. Over the years, cases spread to European countries and reached the Middle East. Therefore, the research conducted by Mariam Souto sought to find out the origin of the disease in Brazil, since the country is not the likely universe for receiving rare cases. One indication, based on the results of the dermatologist's study, is that the disease may have entered the country with European immigration in the 16th century. This is because the specific mutation in Brazilian cases is genetically similar to records of Spanish patients.

Dermatosis evolves into neurological problems and paralysis

Sjögren-Larsson syndrome is an illness resulting from enzyme deficiency and progresses to mental retardation and limb paralysis. The main symptoms appear in the first days of life, when the baby's skin is born dry and similar to fish scales, a type of ichthyosis that lasts forever, causing discomfort and itching in the patient. “Life expectancy is variable, but with low quality”, informs the dermatologist. The diagnosis is not simple and depends on a series of evaluations by professional geneticists, neurologists and dermatologists. It is a disease called autosomal recessive – the patient's parents do not have the disease, but are carriers of the gene that causes it. “In most cases, the parents are close relatives, a factor that increases the risk of acquiring the syndrome”, explains the researcher.

Mariam Souto's interest in this rare disease arose about four years ago, when she was undertaking a medical residency in dermatology at Hospital das Clínicas (HC) at Unicamp. In contact with two brothers who had the disease and accompanying the pregnant mother of a third child at risk of also contracting the syndrome, the dermatologist sensed that she could mitigate the progression of the disease in the unborn baby. To this end, she included a fat-free diet in the child's treatment in the first months of life, as the problem arises from the metabolism of lipids in the body. The proposal was successful, with the help of gastropediatrician Edgar Collares. “The child has mild neurological changes and his general condition is better than that of his siblings who are also sick and not treated,” she says. The experiment, however, cannot be seen as scientific proof, as it was carried out in only one case.

Larger group – Secondly, Mariam Souto set out to study the clinical, histological, structural and molecular aspects of ten patients followed at the HC. Among children and adults, the research consisted of several stages to characterize Brazilian cases of the disease. The use of digital images to analyze skin texture made it possible to understand the changes that led to the disease. “Changes in the architecture of the skin were detected, which were not possible to see with a microscope,” he says. This study was carried out at the Department of Pathological Anatomy, under the guidance of professors Konradin Metze and Maria Letícia Cintra, in addition to professor Neucimar Leite, from the Computing Institute (IC) at Unicamp. Part of the research took place at the Center for Molecular Biology and Genetic Engineering (CBMEG), guided by professor Edi Lúcia Sartorato. There was also the collaboration of American researcher William Rizzo, from the University of Nebraska, who discovered the biochemical defect of the disease.