[Neurofibromatosis type 1 - a malignant evolution in pediatric age]. / Neurofibromatose tipo 1 - uma evolução maligna em idade pediátrica.

Neurofibromatosis type 1 is an autosomal dominant disease affecting one in 3000 to one in 4000 people, with a great variability of clinical expression. Individuals affected with neurofibromatosis type 1 have an increased risk of developing both benign and malignant tumors, supporting the classification of tumor predisposition syndrome. The most common tumor is the neurofibroma, a heterogeneous benign nerve sheath tumor, which represents the primary clinical characteristic of neurofibromatosis. The case reported refers to a adolescent boy with neurofibromatosis type 1 diagnosed at 20 months, who presented progressive growth of dorsal and lumbar intraspinal tumors since six years of age and diagnosis of malignant nerve sheath tumors at 17 years of age. In addition to describing a rare presentation of neurofibromatosis, because of location and early onset of complications, the authors discuss the difficulties of the therapeutic approach of this case.

Neonatal pyruvate dehydrogenase deficiency due to a R302H mutation in the PDHA1 gene: MRI findings.

Pyruvate dehydrogenase (PDH) deficiency is one of the most common causes of congenital lactic acidosis. Correlations between the genetic defect and neuroimaging findings are lacking. We present conventional and diffusion-weighted MRI findings in a 7-day-old male neonate with PDH deficiency due to a mosaicism for the R302H mutation in the PDHA1 gene. Corpus callosum dysgenesis, widespread increased diffusion in the white matter, and bilateral subependymal cysts were the main features. Although confirmation of PDH deficiency depends on specialized biochemical analyses, neonatal MRI plays a role in evaluating the pattern and extent of brain damage, and potentially in early diagnosis and clinical decision making.