[Moderately differentiated squamous cell carcinoma associated pilonidal cyst]. / Tumor epidermoide moderadamente diferenciado asociado con quiste pilonidal.

BACKGROUND: Malignant degeneration of pilonidal sinus is a rare complication observed mainly in recurrent chronic cases of the disease, associated to a very bad prognosis. In the world's literature we find it like an infrequent entity. In Spain had reviewed 367 patients with simple and complicated pilonidal cysts. We found three cases (0.81%) of epidermoid carcinoma. CLINICAL CASE: Men's 60 years of age, with clinical picture of 50 years of evolution with the presence of sacral tumor, is resection and histopathological reporting of pilonidal cyst; taking evolution at healing, with necrotic edges; resection of these will decide and report is squamous cell carcinoma. CONCLUSIONS: Pilonidal sinus epidermoid carcinoma is an infrequent disease predicting for very poor outcome.

Antecedentes: la degeneración maligna es una complicación rara, observada principalmente en enfermedad pilonidal crónica recurrente y se asocia con muy mal pronóstico. En la bibliografía mundial se encuentra como una entidad poco frecuente. En España se revisaron 367 pacientes afectados de quiste pilonidal, simple o complicado. Entre ellos se encontraron tres casos (0.81%) de carcinoma epidermoide con quiste pilonidal. Caso clínico: paciente masculino de 60 años de edad, con cuadro clínico de 50 años de evolución de un tumor sacro. Luego de la exéresis el reporte histopatológico fue de quiste pilonidal; la evolución fue tórpida en la cicatrización, con bordes necróticos que se resecaron y el reporte fue: carcinoma epidermoide. Conclusión: el carcinoma epidermoide de sinus pilonidal es una enfermedad infrecuente asociada con muy mal pronóstico.

Helicobacter pylori genotyping from American indigenous groups shows novel Amerindian vacA and cagA alleles and Asian, African and European admixture.

It is valuable to extend genotyping studies of Helicobacter pylori to strains from indigenous communities across the world to better define adaption, evolution, and associated diseases. We aimed to genetically characterize both human individuals and their infecting H. pylori from indigenous communities of Mexico, and to compare them with those from other human groups. We studied individuals from three indigenous groups, Tarahumaras from the North, Huichols from the West and Nahuas from the center of Mexico. Volunteers were sampled at their community site, DNA was isolated from white blood cells and mtDNA, Y-chromosome, and STR alleles were studied. H. pylori was cultured from gastric juice, and DNA extracted for genotyping of virulence and housekeeping genes. We found Amerindian mtDNA haplogroups (A, B, C, and D), Y-chromosome DYS19T, and Amerindian STRs alleles frequent in the three groups, confirming Amerindian ancestry in these Mexican groups. Concerning H.pylori cagA phylogenetic analyses, although most isolates were of the Western type, a new Amerindian cluster neither Western nor Asian, was formed by some indigenous Mexican, Colombian, Peruvian and Venezuelan isolates. Similarly, vacA phylogenetic analyses showed the existence of a novel Amerindian type in isolates from Alaska, Mexico and Colombia. With hspA strains from Mexico and other American groups clustered within the three major groups, Asian, African or European. Genotyping of housekeeping genes confirmed that Mexican strains formed a novel Asian-related Amerindian group together with strains from remote Amazon Aborigines. This study shows that Mexican indigenous people with Amerindian markers are colonized with H. pylori showing admixture of Asian, European and African strains in genes known to interact with the gastric mucosa. We present evidence of novel Amerindian cagA and vacA alleles in indigenous groups of North and South America.

Characterization of mtDNA haplogroups in 14 Mexican indigenous populations.

In this descriptive study we investigated the genetic structure of 513 Mexican indigenous subjects grouped in 14 populations (Mixteca-Alta, Mixteca-Baja, Otomi, Purépecha, Tzeltal, Tarahumara, Huichol, Nahua-Atocpan, Nahua-Xochimilco, Nahua-Zitlala, Nahua-Chilacachapa, Nahua-Ixhuatlancillo, Nahua-Necoxtla, and Nahua-Coyolillo) based on mtDNA haplogroups. These communities are geographically and culturally isolated; parents and grandparents were born in the community. Our data show that 98.6% of the mtDNA was distributed in haplogroups A1, A2, B1, B2, C1, C2, D1, and D2. Haplotype X6 was present in the Tarahumara (1/53) and Huichol (3/15), and haplotype L was present in the Nahua-Coyolillo (3/38). The first two principal components accounted for 95.9% of the total variation in the sample. The mtDNA haplogroup frequencies in the Purépecha and Zitlala were intermediate to cluster 1 (Otomi, Nahua-Ixhuatlancillo, Nahua-Xochimilco, Mixteca-Baja, and Tzeltal) and cluster 2 (Nahua-Necoxtla, Nahua-Atocpan, and Nahua-Chilacachapa). The Huichol, Tarahumara, Mixteca-Alta, and Nahua-Coyolillo were separated from the rest of the populations. According to these findings, the distribution of mtDNA haplogroups found in Mexican indigenous groups is similar to other Amerindian haplogroups, except for the African haplogroup found in one population.

Severe congenital muscular dystrophy in a Mexican family with a new nonsense mutation (R2578X) in the laminin alpha-2 gene.

The congenital muscular dystrophies (CMDs) are a heterogeneous group of autosomal recessive disorders. Approximately one half of cases diagnosed with classic CMD show primary deficiency of the laminin alpha2 chain of merosin. Complete absence of this protein is usually associated with a severe phenotype characterized by drastic muscle weakness and characteristic changes in white matter in cerebral magnetic resonance imaging (MRI). Here we report an 8-month-old Mexican female infant, from a consanguineous family, with classical CMD. Serum creatine kinase was elevated, muscle biopsy showed dystrophic changes, and there were abnormalities in brain MRI. Immunofluorescence analysis demonstrated the complete absence of laminin alpha2. In contrast, expression of alpha-, beta-, gamma-, and delta-sarcoglycans and dystrophin, all components of the dystrophin-glycoprotein complex, appeared normal. A homozygous C long right arrow T substitution at position 7781 that generated a stop codon in the G domain of the protein was identified by mutation analysis of the laminin alpha2 gene ( LAMA2). Sequence analysis on available DNA samples of the family showed that parents and other relatives were carriers of the mutation.

Avances en distrofias musculares / Advances in muscular dystrophies

Las distrofias musculares son un grupo de enfermedades heredadas que se pueden iniciar en etapas que van desde el nacimiento hasta la edad adulta. Existen varios tipos pero en todos se observa debilidad y pérdida progresiva del músculo que conllevan a pérdida de la fuerza muscular, discapacidad gradual y algunas veces ocasionan deformidades. Estas enfermedades se pueden clasificar de acuerdo con los músculos involucrados, modelo de herencia y edad de inicio. Sin embargo, la identificación reciente de varios genes y proteínas responsables de estas patologías ha incrementado la heterogeneidad genética y clínica, modificando criterios de clasificación e incorporando conocimientos nuevos en la fisiopatología de dichas enfermedades. Así mismo, con el uso de métodos de genética molecular y bioquímicos es factible realizar el diagnóstico preciso de estos padecimientos y hacer una correlación entre la clínica y los defectos genéticos.