Producción CyT
Abstracts - Molecular diagnosis of Junctional Epidermolysis Bullosa: two cases report
Congreso
Fecha:
2017Editorial y Lugar de Edición:
International Society of DermatologyResumen *
Junctional epidermolysis bullosa (JEB) is a recessively inherited epidermolysis characterized by blister formation within the lamina lucida zone of the basement membrane. Subtypes of JEB include severe lethal forms (Herlitz JEB) presenting generalized blistering and systemic involvement (mainly gastrointestinal) and less severe localized forms, also called non-Herlitz JEB. More than 100 pathogenic variants have been described in LAMA3, LAMB3 o LAMC2 genes which encode the three polypeptide chains α3, β3 and γ2 of laminin 5.We present 2 patients clinically and molecularly diagnosed EBJ in our institution. Case1. A seven-year-old boy with congenital generalized blistering, presenting teeth and nail anomalies, granulomatous nasal periorificial ulcers and extensive mucous membrane lesions with severe anemia resulting in failure to thrive. Electronic microscopy of a skin biopsy was inconclusive. Molecular diagnosis revealed the presence of two mutations on LAMB3 gene; R635X, which is a worldwide recurrent mutation detected on the paternal allele and c.3228+1G>A on intron 21 affecting the donor splice site found exclusively in southern cone population.Case 2. A 14-year-old male developed acral and periorificial skin blistering shortly after birth. Presented nail and teeth anomalies, with little mucous membrane and systemic involvement. LAMB3 intronic 3228+1G>A mutation was detected homozygously in this patient.Discussion. Intronic LAMB3 3228+1G>A mutation was found in both patients, one heterozygous and the other homozygous. This mutation was reported so far exclusively in Hispanic patients. Remarkably, the phenotype of both patients differs widely, with a severe case 1 patient and a better prognosis patient as presented in case 2. Conclusion. JEB was diagnosed in two patients using molecular techniques carried out for the first time in our country. Having an unequivocal diagnosis allowed us to improve the therapeutic management. Our patients’ survival is higher than expected for this pathology. One of the mutations found was previously detected in the south cone population. Información suministrada por el agente en SIGEVAPalabras Clave
MOLECULAR DIAGNOSISGENODERMATOSISNGSJUNCTIONAL EPIDERMOLYSIS BULLOSA