Síndrome de Nijmegen: una enfermedad genética a considerar en un paciente con microcefalia, retardo mental y lesiones de la piel / Nijmegen breakage syndrome

Se presenta el caso de un paciente masculino que a los 6 años de edad es derivado a Neurología Infantil para su estudio por presentar microcefalia y retardo mental. Tras ser evaluado por Inmunología y Genética se realiza en el Laboratorio de citogenética humana, programa de genética ICBM, Facultad de Medicina Universidad de Chile, PCR para deleción 657 del5 que confirma el diagnóstico de Nijmegen dando como resultado deleción nucleótido 5, mutación 657 del5, característico del Síndrome de Nijmegen. Actualmente el niño tiene 13 años y es tratado en el Servicio de Oncología infantil por el desarrollo de linfoma difuso de células grandes B, patología frecuente en este sindrome.

A case of a male patient at 6 years old was referred to child neurology for study due to microcephaly and mental retardation. After being evaluated for Immunology and Genetics Laboratory is performed in human cytogenetics, genetic program ICBM, Faculty of Medicine University of Chile, PCR for deletion 657 of the 5 that confirms the diagnosis of Nijmegen nucleotide deletion resulting in 5, 657 mutation del 5 Characteristic of the syndrome of Nijmegen. Currently the child is 13 and is treated at the Children’s Oncology Service in the development of lymphoma diffuse large B cell, common pathology in this syndrome.

Differentiation of Nijmegen breakage syndrome from Fanconi anemia

Nijmegen breakage syndrome (NBS) is a rare auto-somal recessive condition with chromosomal instability. Clinical and biological overlap between Fanconi anemia and ataxia telangiectasia has been reported. We report two cases of NBS born to consanguineous parents. Case one had NBS and Falconi anemia clinical features but relatively little chromosome breakage. The second case had mild NBS features, while cytogenetic evaluation with mitomycin C induction showed chromosome damage. Chromosomal analysis of bone marrow cells revealed tetraploidy, which indicates progression towards leukemia. On the basis of clinical and cytogenetic evaluation, these two cases were confirmed as NBS. However, detailed molecular studies are essential for accurate diagnosis and management of this disease.