Bone Remodeling and Bone Structural Genes in Legg-Calvé-Perthes Disease: The OPG rs2073618 and IL-6 rs1800795 Are Associated with High Risk in Mexican Patients.

Legg-Calve-Perthes disease (LCPD) is an idiopathic avascular necrosis of the pediatric femoral head. Bone remodeling and bone structural genes have the potential to contribute to the progression of LCPD when there is disequilibrium between bone resorption and bone formation. A case-control study was performed to search for associations of several common polymorphisms in the genes Receptor Activator for Nuclear Factor κappa B (RANK), Receptor Activator for Nuclear Factor κappa B Ligand (RANKL), osteoprotegerin (OPG), interleukin (IL)-6, and type 1 collagen (COL1A1) with LCPD susceptibility in Mexican children. A total of 23 children with LCPD and 46 healthy controls were genotyped for seven polymorphisms (rs3018362, rs12585014, rs2073618, rs1800795, rs1800796, rs1800012, and rs2586498) in the RANK, RANKL, OPG, IL-6, and COL1A1 genes by real-time polymerase chain reaction with TaqMan probes. The variant allele (C) of IL-6 rs1800795 was associated with increased risk of LCPD (odds ratio [OR]: 3.8, 95% confidence interval [CI]: [1.08-13.54], p = 0.033), adjusting data by body mass index (BMI) and coagulation factor V (FV), the association with increased risk remained (OR: 4.9, 95% CI: [1.14-21.04], p = 0.025). The OPG polymorphism rs2073618, specifically GC-GG carriers, was associated with a more than fourfold increased risk of developing LCPD (OR: 4.34, 95% CI: [1.04-18.12], p = 0.033) when data were adjusted by BMI-FV. There was no significant association between RANK rs3018362, RANKL rs12585014, IL-6 rs1800796, COL1A1 rs1800012, and rs2586498 polymorphisms and LCPD in a sample of Mexican children. The rs1800975 and rs2037618 polymorphisms in the IL-6 and OPG genes, respectively, are informative markers of increased risk of LCPD in Mexican children.

New Genetic Variants of RUNX2 in Mexican Families Cause Cleidocranial Dysplasia.

Cleidocranial dysplasia (CCD) is an autosomal dominant skeletal dysplasia characterized by persistent open skull sutures with bulging calvaria, hypoplasia, or aplasia of clavicles permitting abnormal opposition of the shoulders; wide public symphysis; short middle phalanx of the fifth fingers; and vertebral, craniofacial, and dental anomalies. It is a rare disease, with a prevalence of 1-9/1,000,000, high penetrance, and variable expression. The gene responsible for CCD is the Runt-related transcription factor 2 (RUNX2) gene. We characterize the clinical, genetic, and bioinformatic results of four CCD cases: two cases within Mexican families with six affected members, nine asymptomatic individuals, and two sporadic cases with CCD, with one hundred healthy controls. Genomic DNA analyses of the RUNX2 gene were performed for Sanger sequencing. Bioinformatics tools were used to predict the function, stability, and structural changes of the mutated RUNX2 proteins. Three novel heterozygous mutations (c.651_652delTA; c.538_539delinsCA; c.662T>A) and a previously reported mutation (c.674G>A) were detected. In silico analysis showed that all mutations had functional, stability-related, and structural alterations in the RUNX2 protein. Our results show novel mutations that enrich the pool of RUNX2 gene mutations with CCD. Moreover, the proband 1 presented clinical data not previously reported that could represent an expanded phenotype of severe expression.

Prothrombin Time and Coagulation Factor IX as Hemostatic Risk Markers for Legg- Calvé-Perthes Disease.

BACKGROUND: Legg-Calvé-Perthes disease (LCPD) is a pediatric disorder that occurs due to the avascular necrosis of the femoral head and affects the range of motion of the hip in various degrees. Its etiology is still unknown, although it has been associated with coagulation abnormalities, however, the lack of reproducibility in the results in various studies has created a controversy as to whether hemostasis disorders are related to LCPD. On the other hand, there is little information on laboratory studies that could facilitate the diagnosis and treatment of LCPD. METHODS: Blood and plasma samples were tested from 25 patients with LCPD and 50 healthy controls, matched by sex and age. Cellular markers were evaluated through complete blood count, as well as coagulation times, coagulation factors activity, antithrombotic proteins, and homocysteine concentration. RESULTS: After assessing activity value frequencies in each group, the results showed more significant activity in some of the biological risk markers of thrombophilia, presenting a substantial difference in prothrombin time↘, FV↗, FVIII↗, FIX↗, and Hcy↗. These values imply that there may be hypercoagulable states in patients, which can cause thrombotic events. CONCLUSIONS: Diminished prothrombin time and increase in FV activity, FVIII, FIX, and Hcy concentration support the hypothesis that microthrombi formation in small-caliber vessels could be causing avascularity and femoral necrosis, which are traits of LCPD. In addition, based on our results, we believe that the laboratory studies carried out are very useful in the diagnosis and treatment of LCPD.

Association of Polymorphisms in Estrogen Receptor Genes (ESR1 and ESR2) with Osteoporosis and Fracture-Involvement of Comorbidities and Epistasis.

Single-nucleotide polymorphisms (SNPs) in the ESR1/ESR2 genes play a role in osteoporosis (OP). Our objective was to determine associations of polymorphisms in ESR genes with OP and fracture, SNP-SNP interactions, and involvement of comorbidities. We analyzed 170 Mexican osteoporotic women (FNOP), 173 with hip fracture (HFx), and 210 controls. The SNPs, ESR1 rs2234693CC, rs851982CC and rs1999805AA, were associated with reduced OP risk (odds ratios [ORs] = 0.35, 0.40 and 0.32, respectively; p < 0.05); rs2234693CC was associated with reduced fracture risk (OR = 0.24; p < 0.05). The obese/overweight carriers of rs9340799GG had a lower OP (OR = 0.15, p = 0.016) and fracture (OR = 0.12, p = 0.0057) risk. The rs9479055AA and rs3020404AA hypertensive carriers had a higher OP risk (OR = 5.96, p = 0.032; and OR = 5.29, p = 0.02, respectively). In addition, rs3020404AA had a higher risk of fracture (OR = 4.90, p = 0.045). The rs2228480GG hypertensive carriers had a higher risk of fracture (OR = 6.22, p = 0.0038). We found a synergic relation between the ESR1 rs3020331 and rs1999805 in femoral neck OP and HFx. The rs2234693 (PvuII) and rs9340799 (XbaI) polymorphisms are associated with a high risk forming a haplotype. The epistasis analysis suggests the contribution of both genes (ESR1/ESR2) to the risk of OP and fracture. Epistasis and involvement of obesity and hypertension lead to a significant modification of the risk.

Legg-Calvé-Perthes disease overview.

BACKGROUND: Legg-Calvé-Perthes Disease (LCPD) is a necrosis of the femoral head which affects the range of motion of the hips. Its incidence is variable, ranging from 0.4/100,000 to 29.0/ 100,000 children. Although LCPD was first described in the beginning of the past century, limited is known about its etiology. Our objective is to describe the main areas of interest in Legg-Calve-Perthes disease. METHODS: A review of the literature regarding LCPD etiology was performed, considering the following inclusion criteria: Studies reporting clinical or preclinical results. The research group carried out a filtered search on the PubMed and Science Direct databases. To maximize the suitability of the search results, we combined the terms ''Perthes disease" OR "LCPD" OR "children avascular femoral head necrosis" with "diagnostic" OR "treatment" OR "etiology" as either key words or MeSH terms. RESULTS: In this article been described some areas of interest in LCPD, we include topics such as: history, incidence, pathogenesis, diagnosis, treatment and possible etiology, since LCPD has an unknown etiology. CONCLUSIONS: This review suggests that LCPD has a multifactorial etiology where environmental, metabolic and genetic agents could be involved.

Association of MTHFR rs1801133 and homocysteine with Legg-Calvé-Perthes disease in Mexican patients.

BACKGROUND: Legg-Calvé-Perthes disease (LCPD) is the avascular osteonecrosis of the proximal femoral epiphysis. It is a rare disease of unclear etiology in children, although alterations in coagulation or the collagen gene have been described and could be associated with its etiology. Our objective was to evaluate the following alterations: COL1A1 (rs1107946, rs2412298), COL2A1 (rs121912891 and rs387106558), MTHFR rs1801133, CBS rs115742905, and PT rs1799963 and their relationship with LCPD. METHODS: DNA was obtained and genotyped by real-time PCR with TaqMan probes. Prothrombin (FII) and homocysteine (Hcy) were determined by a coagulometric method. The variables were described as mean and standard deviation or percentages, and genotypic and allelic distributions were analyzed using the Student's t-test. The Hardy-Weinberg equilibrium and OR were also used. RESULTS: We studied 23 patients with LCPD and 46 controls. We did not find any association of the MTHFR, CBS, PT, COL1A1, and COL2A1 genetic variants with LCPD. However, when adjusting the data with the Hcy values for the MTHFR C677T polymorphism, the C/C genotypes showed an association with the recessive model (p = 0.038), with susceptibility to LCPD. CONCLUSION: No association was found with the CBS, PT, COL1A1, and COL2A1 genes. Nevertheless, our results suggest a significant link between moderately elevated Hcy levels and the MTHFR C677T polymorphism in a cohort of Mexican children with LCPD.

Microbial biofilms and their impact on medical areas: physiopathology, diagnosis and treatment. / Biopelículas microbianas y su impacto en áreas médicas: fisiopatología, diagnóstico y tratamiento

Biofilms are communities of microorganisms that grow aggregated and surrounded by an extracellular matrix, which they produce and favors them to adhere covalently to inert and living surfaces; it also helps them to develop high tolerance to molecules with antimicrobial activity. Moreover, biofilms are associated with chronic and persistent infections, which negatively impact different medical areas since they generate high costs to health care systems and patients every year because they are difficult to treat with conventional antimicrobial drugs. Additionally, they generate high rates of morbidity and mortality. The objective of this review was to present extensive and up-to-date information on the origin, biosynthesis, and pathophysiology of biofilms. Also, its relationship with chronic infections, diagnosis, current antimicrobial treatments with antibiotic activity, and perspectives on the search for new treatments, since the latter still represent an important area of research.

Las biopelículas son comunidades de microorganismos que crecen agregados y rodeados por una matriz extracelular que ellos mismos producen, la cual favorece la adhesión covalente sobre superficies inertes y vivas; además, les ayuda a desarrollar alta tolerancia a las moléculas con actividad antimicrobiana. Por otra parte, las biopelículas se asocian con infecciones crónicas y persistentes que impactan de manera negativa en distintas áreas médicas. Además, generan altos costos a los sistemas de salud y a los pacientes cada año, porque son difíciles de tratar con antimicrobianos convencionales; adicionalmente, generan altas tasas de morbilidad y mortalidad. El objetivo de esta revisión es presentar información extensa y actualizada sobre el origen, la biosíntesis y la fisiopatología de las biopelículas, así como sobre su relación con infecciones crónicas, el diagnóstico, los tratamientos antimicrobianos actuales con actividad antibiopelícula y las perspectivas sobre la búsqueda de nuevos tratamientos. Estos últimos aún representan una importante área de investigación.

Biopelículas microbianas y su impacto en áreas médicas: fisiopatología, diagnóstico y tratamiento / Microbial biofilms and their impact on medical areas: physiopathology, diagnosis and treatment

Resumen Las biopelículas son comunidades de microorganismos que crecen agregados y rodeados por una matriz extracelular que ellos mismos producen, la cual favorece la adhesión covalente sobre superficies inertes y vivas; además, les ayuda a desarrollar alta tolerancia a las moléculas con actividad antimicrobiana. Por otra parte, las biopelículas se asocian con infecciones crónicas y persistentes que impactan de manera negativa en distintas áreas médicas. Además, generan altos costos a los sistemas de salud y a los pacientes cada año, porque son difíciles de tratar con antimicrobianos convencionales; adicionalmente, generan altas tasas de morbilidad y mortalidad. El objetivo de esta revisión es presentar información extensa y actualizada sobre el origen, la biosíntesis y la fisiopatología de las biopelículas, así como sobre su relación con infecciones crónicas, el diagnóstico, los tratamientos antimicrobianos actuales con actividad antibiopelícula y las perspectivas sobre la búsqueda de nuevos tratamientos. Estos últimos aún representan una importante área de investigación.

Abstract Biofilms are communities of microorganisms that grow aggregated and surrounded by an extracellular matrix, which they produce and favors them to adhere covalently to inert and living surfaces; it also helps them to develop high tolerance to molecules with antimicrobial activity. Moreover, biofilms are associated with chronic and persistent infections, which negatively impact different medical areas since they generate high costs to health care systems and patients every year because they are difficult to treat with conventional antimicrobial drugs. Additionally, they generate high rates of morbidity and mortality. The objective of this review was to present extensive and up-to-date information on the origin, biosynthesis, and pathophysiology of biofilms. Also, its relationship with chronic infections, diagnosis, current antimicrobial treatments with antibiotic activity, and perspectives on the search for new treatments, since the latter still represent an important area of research.

Novel pathogenic variants underlie SLC26A4-related hearing loss in a multiethnic cohort.

OBJECTIVES: The genetics of sensorineural hearing loss is characterized by a high degree of heterogeneity. Despite this heterogeneity, DNA variants found within SLC26A4 have been reported to be the second most common contributor after those of GJB2 in many populations. METHODS: Whole exome sequencing and/or Sanger sequencing of SLC26A4 in 117 individuals with sensorineural hearing loss with or without inner ear anomalies but not with goiter from Turkey, Iran, and Mexico were performed. RESULTS: We identified 27 unique SLC26A4 variants in 31 probands. The variants c.1673A > G (p.N558S), c.1708-1G > A, c.1952C > T (p.P651L), and c.2090-1G > A have not been previously reported. The p.N558S variant was detected in two unrelated Mexican families. CONCLUSION: A range of SLC26A4 variants without a common recurrent mutation underlies SLC26A4-related hearing loss in Turkey, Iran, and Mexico.

Characterization of a group unrelated patients with arthrogryposis multiplex congenita / Caracterização de um grupo de pacientes não relacionados com artrogripose múltipla congênita

ABSTRACT OBJECTIVE: Arthrogryposis multiplex congenita is a relatively rare neuromuscular syndrome, with a prevalence of 1:3000-5000 newborns. In this study, the authors describe the clinical features of a group of 50 unrelated Mexican patients with arthrogryposis multiplex congenita. METHODS: Patients were diagnosed by physical and radiographic examination and the family history was evaluated. RESULTS: Of the 50 cases, nine presented other features (pectum excavatum, cleft palate, mental retardation, ulnar agenesis, etc.). Environmental factors, as well as prenatal and family history, were analyzed. The chromosomal anomalies and clinical entities associated with arthrogryposis multiplex congenita were reported. No chromosomal aberrations were present in the cases with mental retardation. Three unrelated familial cases with arthrogryposis multiplex congenita were observed in which autosomal recessive, autosomal dominant and X-linked inheritance patterns are possible. A literature review regarding arthrogryposis multiplex congenita was also conducted. CONCLUSIONS: It is important to establish patient-specific physical therapy and rehabilitation programs. A multidisciplinary approach is necessary, with medical, surgical, rehabilitation, social and psychological care, including genetic counseling.

RESUMO OBJETIVO: A artrogripose múltipla congênita é uma síndrome neuromuscular relativamente rara, com prevalência de 1:3000-5000 recém-nascidos. É por isso que, neste estudo, descrevemos as características clínicas de um grupo de 50 casos de pacientes mexicanos não relacionados com artrogripose múltipla congênita. MÉTODOS: Os pacientes foram diagnosticados por exame físico e radiográfico e o histórico familiar foi avaliado. RESULTADOS: Descrevemos 50 pacientes não relacionados com artrogripose múltipla congênita. Nove deles apresentaram outras características (pectus excavatum, fissura palatina, retardo mental, agenesia da ulna etc.). Foram analisados os fatores ambientais, pré-natais e o histórico familiar. Relatamos as anomalias cromossômicas e as entidades clínicas associadas com a artrogripose múltipla congênita. Não havia aberração cromossômica nos casos com retardo mental. Também encontramos três casos familiares não relacionados com artrogripose múltipla congênita, em que são possíveis padrões de herança autossômica recessiva, autossômica dominante e ligada ao cromossomo X. Também analisamos a preocupação da literatura com a artrogripose múltipla congênita. CONCLUSÕES: Reiteramos a ideia de que é importante estabelecer programas de fisioterapia e reabilitação específicos para os pacientes. É necessária uma abordagem multidisciplinar com cuidado médico, cirúrgico, de reabilitação, social e psicológico, incluindo aconselhamento genético.

Comprehensive analysis via exome sequencing uncovers genetic etiology in autosomal recessive nonsyndromic deafness in a large multiethnic cohort.

PURPOSE: Autosomal recessive nonsyndromic deafness (ARNSD) is characterized by a high degree of genetic heterogeneity, with reported mutations in 58 different genes. This study was designed to detect deafness-causing variants in a multiethnic cohort with ARNSD by using whole-exome sequencing (WES). METHODS: After excluding mutations in the most common gene, GJB2, we performed WES in 160 multiplex families with ARNSD from Turkey, Iran, Mexico, Ecuador, and Puerto Rico to screen for mutations in all known ARNSD genes. RESULTS: We detected ARNSD-causing variants in 90 (56%) families, 54% of which had not been previously reported. Identified mutations were located in 31 known ARNSD genes. The most common genes with mutations were MYO15A (13%), MYO7A (11%), SLC26A4 (10%), TMPRSS3 (9%), TMC1 (8%), ILDR1 (6%), and CDH23 (4%). Nine mutations were detected in multiple families with shared haplotypes, suggesting founder effects. CONCLUSION: We report on a large multiethnic cohort with ARNSD in which comprehensive analysis of all known ARNSD genes identifies causative DNA variants in 56% of the families. In the remaining families, WES allows us to search for causative variants in novel genes, thus improving our ability to explain the underlying etiology in more families.Genet Med 18 4, 364-371.

Characterization of a group unrelated patients with arthrogryposis multiplex congenita.

OBJECTIVE: Arthrogryposis multiplex congenita is a relatively rare neuromuscular syndrome, with a prevalence of 1:3000-5000 newborns. In this study, the authors describe the clinical features of a group of 50 unrelated Mexican patients with arthrogryposis multiplex congenita. METHODS: Patients were diagnosed by physical and radiographic examination and the family history was evaluated. RESULTS: Of the 50 cases, nine presented other features (pectum excavatum, cleft palate, mental retardation, ulnar agenesis, etc.). Environmental factors, as well as prenatal and family history, were analyzed. The chromosomal anomalies and clinical entities associated with arthrogryposis multiplex congenita were reported. No chromosomal aberrations were present in the cases with mental retardation. Three unrelated familial cases with arthrogryposis multiplex congenita were observed in which autosomal recessive, autosomal dominant and X-linked inheritance patterns are possible. A literature review regarding arthrogryposis multiplex congenita was also conducted. CONCLUSIONS: It is important to establish patient-specific physical therapy and rehabilitation programs. A multidisciplinary approach is necessary, with medical, surgical, rehabilitation, social and psychological care, including genetic counseling.

Risk Factors for Thrombosis Development in Mexican Patients.

BACKGROUND: To identify inherited factors: Protein C (PC), protein S (PS), antithrombin (AT), plasminogen (Plg), the activated PC resistance (APCR), prothrombin (PT) mutation G20210 A (PTG20210 A) and methylenetetrahydrofolate reductase C677 T polymorphism (MTHFR C677 T), as well as acquired-risk factors such as: diabetes mellitus, surgeries, smoking, obesity, hypertension, trauma, alcoholism, family history; and their association, in Mexican patients with diagnostic of thrombophilia. METHODS: Overall, 200 patients diagnosed with thrombophilia and 100 healthy controls. Commercial kits were used for the coagulometric tests and polymerase chain reaction, restriction fragment length polymorphism for molecular alterations. RESULTS: Alterations were found with an estimated prevalence to PC 0.65%, AT 2.04% and Plg 2.5%, APCR 2%, PT 20210 2%, and MTHFR 65%. The C677 T polymorphism of the MTHFR did not associate with acquired-risk factors so we can suppose that it is an independent risk factor. For the patients that only presented acquired-risk factors (21 of 200), the association smoking-alcoholism showed to be the cause of thrombosis with high risk. The following were also associated: smoking with AT, PC, and alcoholism; obesity with Plg; smoking with alcoholism, and PS deficiency. CONCLUSIONS: Risk factors for both primary and secondary and their association were present as a cause of thrombosis in the patients studied, and the possibility to suffer a recurrent thrombosis.

[Von Willebrand disease. Molecular biology and diagnosis]. / Enfermedad de von Willebrand, biología molecular y diagnóstico.

BACKGROUND: Von Willebrand disease is the most common inherited disorder of the coagulation proteins in humans. There are three types: 1, 2A, 2B, 2N, 2M and 3. It is associated with mutations on chromosome 12 in the region p13.2, encoding the von Willebrand factor (VWF), which is synthesized in endothelial cells and megakaryocytes. DISCUSSION: The VWF gene has been characterised using molecular biology techniques, which have acquired an important role in diagnosis von Willebrand disease, as well as in the investigation of alterations in other genes, which may be involved in regulating the synthesis, processing, and secretion of VWF. However, there are still no strategies to integrate the molecular biology diagnostic tests available. Analysis of VWF multimers is a methodology that meets the characteristics for diagnosis, but it is not easy to standardise. Considering that even in tertiary centres in our country, von Willebrand patients do not have a definitive diagnosis, it is necessary to implement these methodologies to study and improve diagnosis. CONCLUSIONS: Von Willebrand disease is highly heterogeneous due to the molecular mechanisms that produce the various clinical and laboratory phenotypes. In Mexico there are few studies related to this disease; therefore it is essential to conduct a comprehensive study including clinical, basic, and special testing laboratory tests, in order to establish a correct diagnosis, develop new therapeutic approaches, and offer the appropriate medical care and genetic counselling.

Anticoagulant proteins in a population of Mexican mestizo donors.

BACKGROUND: To determine the activity of antithrombin (AT), protein C (PC), and protein S (PS), as well as the frequency of deficiencies of these proteins in a population of healthy Mexican mestizo blood donors. METHODS: AT, PC, and PS were determined from 1,502 plasma samples of healthy blood donors by using commercial kits in a coagulometer 4 STA (Diagnostica Stago, Asnières, France). RESULTS: A total of 741 women and 761 men were under study. They were divided into age range groups (18-24, 25-34, 35-44, 45-54, and 55-64 years). Activity of AT, PC, and PS was determined. For AT, activity values were specific for each age group according to gender when it had to do with PS, as well as when PC was determined. Frequencies of AT, PC, PS, and activated PC resistance activity deficiencies were obtained from reference levels (RLs) and average levels of this study. Differences were found between both frequencies for AT, PC, and PS, and the average levels obtained were used in this study. The frequencies of the activity deficiencies obtained through the values gotten in this population were: AT, 0.6%; PC, 1.06% (which is higher than the one obtained using the RLs described by commercial kits 0.33% and 0.66%, respectively); and PS, 1% (which is less than 4.5%). CONCLUSIONS: It is necessary to know the characteristics and biological behavior of the coagulation proteins in the Mexican population because the RLs used have been established for populations that are genetically different.

[Determination of von Willebrand factor multimers in Mexican population]. / Determinación de los multímeros del factor von Willebrand en población mexicana.

BACKGROUND: Von Willebrand disease is an inherited disease in which the structure, function, and concentration of von Willebrand factor are altered, as well as the platelet von Willebrand factor endothelium interaction. In Mexico there are no epidemiological records of the disease. Only a few isolated studies have been reported from the clinical and hematological standpoint. METHODS: We studied 155 Mexican Mestizos: 75 with presumptive diagnosis of von Willebrand disease, 15 with suspected diagnosis ofhemophilia A and 65 healthy donors (controls). Basic coagulation tests, special tests and classification test (analysis of multimeric composition) were carried out. RESULTS: There were 15 patients with clinical diagnosis of hemophilia A, 75 patients with suspected von Willebrand disease of which 50 were diagnosed as the following types and subtypes: Type 1 (62%), Type 2 (22%) [subtypes: 2A (14%), 2B (2%), and 2N (6%)] and Type 3 (16%). CONCLUSION: It has been reported that analysis of von Willebrand factor is a method that meets the characteristics for the diagnosis of von Willebrand disease. It is necessary to implement this methodology to study and improve the specific diagnoses.

Antecedentes: la enfermedad de von Willebrand es un padecimiento hereditario en el que la estructura, función y concentración del factor de von Willebrand están alteradas y, en consecuencia, también la interacción plaqueta-factor de von Willebrand-endotelio. En México no hay registros epidemiológicos de la enfermedad, sólo se han efectuado algunos estudios aislados desde el punto de vista clínico y hematológico. Material y métodos: estudio retrospectivo efectuado en 155 mexicanos mestizos, 75 de ellos con diagnóstico presuntivo de enfermedad de von Willebrand, 15 con sospecha de hemofilia A y 65 donadores sanos (testigos). Se realizaron pruebas: básicas de coagulación, especiales y de clasificación: análisis de la composición multimérica. Resultados: 15 pacientes se diagnosticaron con hemofilia A; de los 75 sujetos con sospecha de enfermedad de von Willebrand se diagnosticaron 50 de la manera siguiente: tipo 1 (62%), tipo 2 (22%) [subtipos: 2A (14%), 2B (2%) y 2N (6%)] y tipo 3 (16%). Conclusión: el análisis de los multímeros del factor de von Willebrand es un método que cumple con las características adecuadas para el diagnóstico de la enfermedad de von Willebrand, por lo que es necesario implementar esta metodología para su estudio y mejorar su diagnóstico específico.

[The auditory pathway: levels of integration of information and principal neurotransmitters]. / La vía auditiva: niveles de integración de la información y principales neurotransmisores.

In this paper we studied the central auditory pathway (CAP) from an anatomical, physiological and neurochemical standpoint, from the inner ear, brainstem, thalamus to the temporal auditory cortex. The characteristics of the spiral ganglion of Corti, auditory nerve, cochlear nuclei, superior olivary complex, lateral lemniscus, inferior colliculus, medial geniculate body, and auditory cortex, including the auditory efferent pathway, are given. CAP is described as the electrical impulses, travelling through axons, allowing ions to enter a neuron and vesicles with neurotransmitters (NT) and then released into synaptic space. The NT changes the functioning of the cells; when attached to specific receptors on the next nerve cell, NT-receiver union causes input of ions through Gap sites, resulting in a postsynaptic potential that is spread over all CAP. In addition, the effects of the NT are not limited to the transmission, but as trophic agents that promote the formation of new neural networks. Even the anatomy, physiology, neurochemical aspects, and the different types of synapses are not fully understood to comprehend the organization of the CAP, but remain under investigation because of the relevance for the treatment of various central auditory disorders.

Unique spectrum of GJB2 mutations in Mexico.

OBJECTIVE: The aim of this study was to elucidate the involvement of mutations in three relatively common deafness genes in Mexican individuals with non-syndromic hearing loss. METHODS: We sequenced GJB2 for mutations, screened for two deletions involving GJB6, del(GJB6-D13S1830) and del(GJB6-D13S1854), and for the m.1555A>G mutation in the MTRNR1 gene in 76 (71 simplex and 5 multiplex) unrelated Mexican probands with prelingual non-syndromic hearing loss. Samples were obtained from the Department of Genetics at Instituto Nacional de Rehabilitacion in Mexico City. RESULTS: Eight previously reported pathogenic variants and two polymorphic variants in GJB2 were identified. The two screened GJB6 deletions and the m.1555A>G mutation were not detected. Eight cases (10.6%) were found to have bi-allelic mutations in GJB2 and six (7.9%) were found to have a monoallelic GJB2 mutation. Of the six monoallelic mutations, one (p.R184Q) was a previously reported autosomal dominant variant. The most frequent pathological allele detected in this population was the c.35delG mutation in the GJB2 gene. The p.V27I polymorphic variant was also detected, with an allele frequency of 0.24. All eight probands with GJB2 mutations had symmetric profound deafness, whereas patients without GJB2 mutations had moderate, severe or profound hearing loss. CONCLUSIONS: This study shows that GJB2 mutations are an important cause of prelingual deafness in the Mexican population.

Leiden V factor and spastic cerebral palsy in Mexican children.

AIM: Cerebral palsy (CP) is a persistent motor disorder that appears before the patient is 3 years old due to a nonprogressive interference in the brain's development which takes place before the central nervous system growth is complete. Causes of this have been studied, and one that has been proposed for spastic hemiparesis CP is the Leiden mutation of V factor coagulation. We want to know whether this mutation can cause CP in our population. MATERIALS AND METHODS: We carried out a study of cases and controls with 94 patients with spastic hemiparesis CP and 120 controls as well as their mothers with their controls. RESULTS: None of the patients, their mothers, or controls had the Leiden mutation; however, other risk factors were significant: hypoxia odds ratio (OR) 7.189 (2.546, 20.302) p=0.0001, smoking OR 16.621 (2.945, 93.818) p=0.001, maternal infections (urinary or vaginal) OR 7.040 (2.952, 16.789) p=0.0001, weeks of gestation OR 0.866 (0.7750, 0.999) p=0.048, and maternal age OR 1.114 (1.031, 1.204) p=0.006. CONCLUSION: Leiden mutation of factor V is not an important factor for our Mexican mestizo population; however, there are other important perinatal risk factors.