[Linear Darier disease in two siblings. An example of loss of heterozygosity]. / Maladie de Darier linéaire dans une fratrie. Un exemple de perte d'hétérogénéité.

BACKGROUND: Darier's disease or keratosis follicularis is an autosomal dominant acantholytic disorder that frequently arises as a result of spontaneous mutation. It is either a generalized or localized condition due to a mutation in the SERCA2 12q23-q24,1 resulting in a faulty organization of the tonofilaments. We present two siblings affected with the linear form of this disorder and discuss these cases as an example of the genetic mechanism of loss of heterozygosity. CASE REPORTS: A 7 year-old girl was referred for evaluation of linear lesions present since the first year of age. Examination disclosed red, 1 to 2 mm papules that coalesced to form linear plaques on the left side of the vulvar and perianal areas, and on the left hand and foot. Her older brother had similar lesions in a linear arrangement on the left side of the face neck and homolateral foot. No lesions were found in their parents. Biopsies of both affected children revealed an intraepidermal suprabasal cleft. Dyskeratotic cells were present in the spinous layer, and corps ronds and grains near the granular layer. DISCUSSION: The linear form of Darier's disease could result from genetic mosaicism for this autosomal dominant disorder. As these children have a more pronounced involvement than the usual Darier's disease lesions, disposed in a linear arrangement, they probably represent a type 2 segmental manifestation of the disorder. Likewise, the presence of the same linear disorder in two siblings could be explained by loss of heterozygosity for the Darier's disease gene.

Zigomicosis rino-sinuso-orbital post-traumática / Post-traumatic rhino-sinus-orbital zygomycosis

Se describe un caso de zigomicosis rino-seno-orbital en un paciente sin antecedentes de inmunodeficiencia que presenta exolftalmia izquierda y lesiones infiltrativas edematosas en párpado inferior, nariz y región molar homolateral de rápida evolución. El hallazgo de abundantes hifas hialinas anchas, no tabicadas y tortuosas en biopsia cutánea de fistula intraorbitaria y en secreción nasal, junto a la obtención de cultivos puros de rhizopus oryzae, confirmaron el diagnóstico. La extracción del 2º molar superior izquierdo se interpretó como factor local de implantación traumática del agente etiológico y el reconocimiento de los síntomas clínicos iniciales fue crucial para el diagnóstico precoz. esta micosis no constituye un grave problema de salud, no obstante, en Tucumán debe tenerse presente su existencia

Extensive symmetric truncal aplasia cutis congenita without fetus papyraceus or macroscopic evidence of placental abnormalities.

Aplasia cutis congenita is a rare disorder characterized by localized absence of skin at birth. Type V in Frieden's classification, which is associated with fetus papyraceous or placental infarcts, occurs as a large cutaneous defect on the trunk and extremities. The patient we report had a lesion affecting the trunk and extremities symmetrically, with no family history of the disorder or chromosomal abnormalities. In our opinion, despite the absence of fetus papyraceous or placental infarct, this patient's condition can be classified as type V.