Unraveling the genetic complexities of combined retinal dystrophy and hearing impairment.

Usher syndrome, the most prevalent cause of combined hereditary vision and hearing impairment, is clinically and genetically heterogeneous. Moreover, several conditions with phenotypes overlapping Usher syndrome have been described. This makes the molecular diagnosis of hereditary deaf-blindness challenging. Here, we performed exome sequencing and analysis on 7 Mexican and 52 Iranian probands with combined retinal degeneration and hearing impairment (without intellectual disability). Clinical assessment involved ophthalmological examination and hearing loss questionnaire. Usher syndrome, most frequently due to biallelic variants in MYO7A (USH1B in 16 probands), USH2A (17 probands), and ADGRV1 (USH2C in 7 probands), was diagnosed in 44 of 59 (75%) unrelated probands. Almost half of the identified variants were novel. Nine of 59 (15%) probands displayed other genetic entities with dual sensory impairment, including Alström syndrome (3 patients), cone-rod dystrophy and hearing loss 1 (2 probands), and Heimler syndrome (1 patient). Unexpected findings included one proband each with Scheie syndrome, coenzyme Q10 deficiency, and pseudoxanthoma elasticum. In four probands, including three Usher cases, dual sensory impairment was either modified/aggravated or caused by variants in distinct genes associated with retinal degeneration and/or hearing loss. The overall diagnostic yield of whole exome analysis in our deaf-blind cohort was 92%. Two (3%) probands were partially solved and only 3 (5%) remained without any molecular diagnosis. In many cases, the molecular diagnosis is important to guide genetic counseling, to support prognostic outcomes and decisions with currently available and evolving treatment modalities.

Sordera neurosensorial congénita con malformación de oído interno ligada al X en una familia mexicana / Congenital sensorineural deafness X-linked, with inner ear malformation in a Mexican family

Introducción. Las sorderas o hipoacusias prelinguales son de etiología genética entre el 60 y el 68% de los casos; de estos, del 20 al 40% son malformaciones del oído interno. De los casos de hipoacusia no sindrómica ligada al X se han descrito siete tipos. De las malformaciones de oído interno, la partición coclear incompleta tipo III es la menos frecuente.Objetivo. Presentar el reporte clínico-genético de una familia mexicana, con indi-viduos varones afectados por sordera neurosensorial congénita con malformación de oído interno. Material y Métodos. Se realizó estudio de una familia en la que nueve miembros presentaban sordera. Se estudiaron cuatro de ellos y una madre sin manifestaciones, a través del estudio clínico general por médico genetista, el estudio audiológico (otos-copía y audiometría) por médico audiólogo y el estudio de tomografía computada (TC) por médico radiólogo.Resultados. Los pacientes estudiados presentaron sordera neurosensorial congéni-ta, de severa a profunda bilateral. A través de la TC, se evidenció malformación de oído interno. Tres pacientes presentaron partición coclear incompleta tipo III y un paciente partición incompleta tipo I. Debido al estudio clínico y al árbol genealógico, se definió diagnóstico de hipoacusia neurosensorial no sindrómica ligada al X. La TC de la madre sin manifestaciones no presentó evidencia de malformaciones en oído interno (MOI).Conclusión. El estudio de imagen es fundamental para definir presencia o no de MOI en todos los pacientes con hipoacusia y así poder guiar la terapéutica y el aseso-ramiento genético, así como realizar los estudios moleculares más adecuados

Introduction. The pre-lingual deafness or hearing loss are of genetic cause in be-tween 60% and 68% of cases, among these, between 20% and 40% are malforma-tion of the inner ear. From the non-syndromic hearing loss cases that are linked to the X chromosome, seven types have been described. Among these inner ear malforma-tions, incomplete cochlear partition type III is the less frequent.Objective. Present the clinical genetical report of a Mexican family, with male in-dividuals affected by congenital neurosensory deafness with inner ear malformation.Materials and methodology. A study on a family in which nine members were affected by deafness was done. Four of them, plus a mother without manifestation, were studied through a general clinical study by a geneticist, an audiological study (otoscopy and audiometry) by an audiologist, and a computed tomography (CT) scan by a radiologist.Results. The studied patients presented congenital neurosensory deafness, from se-vere to deep bilateral. Via the CT, the inner ear malformation was made clear. Three of the patients presented incomplete cochlear partition type III and one patient in-complete cochlear partition type I. Due to the clinical study and the family tree, it was diagnosed non-syndromic neurosensory deafness linked to X. The CT of the mother without manifestation did not show evidence of inner ear malformations.Conclusion. The study by image is fundamental to define whether there is or not a presence of inner ear malformations in any patient with heading loss to be able to guide the therapeutics and the genetic counseling, as well as to make more accurate molecular studies

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.

PPARG-LYPLAL1 Multi-Allelic Combination Associated with Obesity and Overweight in Mexican Adolescent Females.

OBJECTIVE: We studied multi-loci variants to identify the contribution of six candidate genes (ADIPOQ, CDH13, LYPLAL1, MC4R, PPARG and PGC1A) in the development of obesity and overweight. DESIGN: We genotyped 404 chromosomes with eleven SNPs in Mexican female adolescents, who were subdivided into two groups (obesity-overweight and normal-weight) using the World Health Organization parameters. Genomic (800 chromosomes) and ancestral (208 chromosomes) controls were included to reduce the population bias. Anthropometric measurements, biochemical parameters, and caloric intake were obtained only in the groups of Mexican female adolescents. RESULTS: A positive genotype-phenotype association was found that involves the multi-allelic combination of three risk alleles (one in PPARG and two in LYPLAL1) with obesity and overweight (OR=3.1, P=.010). This combination also exhibited a significant association with waist circumference (P=.030) and triglycerides levels (P=.030). These associations were supported by a logistic regression analysis adjusted for several confounding variables. CONCLUSIONS: Our data suggest the joint participation of PPARG-LYPLAL1 genes in metabolic disorders development. Hence, these genes could act as potential biomarkers in obesity and overweight. Our findings underscore the complexity of metabolic disorders and provide evidence about the importance of multi-loci analysis to study complex diseases.

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.

Association of resistance to activated protein with the presence of Leiden and Cambridge Factor V mutations in Mexican patients with primary thrombophilia.

BACKGROUND: Leiden and Cambridge factor V coagulation mutations and activated protein C resistance (RaPC) are alterations related with vein and artery thrombosis. In this study we aimed to determine whether RaPC is associated with the presence of Leiden and Cambridge mutation and the frequency of these mutations in the racially mestizo Mexican population. METHODS: We included 150 Mexican patients with primary thrombophilia and 100 healthy subjects in this study. RaPC was determined using commercial methods and genotypes FV Leiden and FV Cambridge with PCR-RFLPs. RESULTS: RaPC was positive in four patients and in one control individual; however, there was no presence of Leiden or Cambridge mutation in the studied group; thus, RaPC was not correlated with the presence of any of the studied mutations. CONCLUSIONS: These results indicate that there are other primary or secondary causes different from those studied, which condition the presence of RaPC. Furthermore, the frequency obtained for RaPC in our thrombophilic population of racially mixed Mexicans is lower compared to that obtained in the Caucasian population, most probably because they are genetically different populations.

Asociación de la RPCA con mutaciones Leiden y Cambridge del factor V de la coagulación en pacientes mexicanos con trombofilia primaria / Association of resistance to activated protein with the presence of Leiden and Cambridge Factor V mutations in Mexican patients with primary thrombophilia

Introducción: Las mutaciones Leiden y Cambridge del factor V de la coagulación y la resistencia a la proteína C activada (RPCA) son alteraciones que se relacionan con trombosis venosa y arterial. En este trabajo se analizó si la RPCA está asociada con las mutaciones Leiden y Cambridge, y la frecuencia de éstas en población mestiza mexicana. Material y métodos: Se incluyeron 150 pacientes mexicanos con trombofilia primaria y 100 sujetos sanos. Se determinó la RPCA empleando método comercial y los genotipos factor V Leiden y factor V Cambridge mediante PCR-RFLPs. Resultados: La RPCA fue positiva en cuatro pacientes y en un individuo control; sin embargo, no se encontró la mutación Leiden o Cambridge en la población estudiada, por lo que la RPCA no se correlacionó con ninguna de las mutaciones investigadas. Conclusiones: Los resultados indican que existen otras causas primarias o secundarias diferentes a las analizadas, que condicionan la RPCA. Además, la frecuencia obtenida para la RPCA en nuestra población trombofílica mestiza mexicana fue menor comparada con la obtenida en población caucásica, quizá por tratarse de poblaciones genéticamente diferentes.

BACKGROUND: Leiden and Cambridge factor V coagulation mutations and activated protein C resistance (RaPC) are alterations related with vein and artery thrombosis. In this study we aimed to determine whether RaPC is associated with the presence of Leiden and Cambridge mutation and the frequency of these mutations in the racially mestizo Mexican population. METHODS: We included 150 Mexican patients with primary thrombophilia and 100 healthy subjects in this study. RaPC was determined using commercial methods and genotypes FV Leiden and FV Cambridge with PCR-RFLPs. RESULTS: RaPC was positive in four patients and in one control individual; however, there was no presence of Leiden or Cambridge mutation in the studied group; thus, RaPC was not correlated with the presence of any of the studied mutations. CONCLUSIONS: These results indicate that there are other primary or secondary causes different from those studied, which condition the presence of RaPC. Furthermore, the frequency obtained for RaPC in our thrombophilic population of racially mixed Mexicans is lower compared to that obtained in the Caucasian population, most probably because they are genetically different populations.

La electroforesis capilar como una nueva estrategia en la medicina y el diagnóstico clínico / Capillary electrophoresis, a new diagnostic tool

Capillary electrophoresis (CE) may replace many conventional clinical laboratory methods, such as electrophoresis, Southern blotting, sequencing and HPLC (High-performance liquid chromatography). It is an ideal technique due to analytical speed, the possibility of handling great amount of samples, its capacity to separate small molecules according to their size, charge, hydrophobic and stereo-specificity its good reproducibility the use of small amounts of sample and reagents, its low costs and easy handling. The diagnosis of hereditary diseases or the predisposition to polygenic diseases related to specific mutations or polymorphisms can be carried out with this method. In clinical laboratories, this technique is being used for the analysis of several substrates present in urine or serum and for the diagnosis of some infectious agents. It is also a firsthand tool in forensic medicine for human identification and anthropology.

[Diagnosis of the peripheral hereditary neuropathies and its molecular genetics]. / El diagnóstico de las neuropatías periféricas hereditarias y la genética molecular.

Peripheral neuropathies include a wide range of pathological disorders characterized by damage of peripheral nerves. Among them, peripheral hereditary neuropathies are a group of frequent illnesses and early evolution. They have been named hereditary motor and sensory neuropathy (HMSN) or peripheral hereditary neuropathies type Charcot-Marie-Tooth (CMT). The most frequent types are CMT1, CMT2 and CMTX. Approximately 70% of the cases correspond to subtype CMT1A, associated with tandem duplication of a 1.5 Mb DNA fragment on chromosome 17p11.2-p12 that codifies the peripheral myelin protein PMP22. So far, there five different types of CMT (1,2,3,4,X) with approximately 32 subtypes, associated with more than 30 genes. Have been reported genetic heterogeneity and expression variability of the illness makes it necessary to carry on diagnostic strategies that integrate clinical study for determining genetic clinical history, family history, complete physical exploration, muscular strength, physical deformities, reflexes and sensitivity, and molecular studies allow detection of different types of mutations and help establish a correct diagnosis and an adequate genetic counseling.

[Microarray design using virtual hybridization to study variations in REP-CMT1A sites]. / Diseño de microsondas mediante hibridación virtual para el estudio de variantes en los sitios REP-CMT1A.

BACKGROUND: Gene PMP22 is duplicated in patients with CMT1A. Duplication is due to an unequal chromatid interchange during meiosis that takes place between two 24 Kb regions named REP-CMT1A proximal and distal sites. Homology is approximately 98%. Within each one of the sites we find zones termed hot spots where a greater number of variants and mutations could give origin to an unequal interchange. The aim of this study was to design a set of probes to create a microarray that could detect the presence of variants and mutation points in distal and proximal REP sites among patients with CMT1A. MATERIAL AND METHODS: With reported sequences of distal and proximal REPs, we determined hot spot sites within proximal and distal regions. These sequences were aligned and matched, hence 12 zones were detected. RESULTS AND CONCLUSIONS: Twenty four probes were designed and analyzed using the Genosensor Probe Designer program. Probes could be synthesized and used in a microarray that is able to find variations and mutation points and facilitates diagnosis of patients with CMT1A.

Diseño de microsondas mediante hibridación virtual para el estudio de variantes en los sitios REP-CMT1A / Microarray design using virtual hybridization to study variations in REP-CMT1A sites

Antecedentes: El gen PMP22 se encuentra duplicado en pacientes con Charcot-Marie-Tooth 1A (CMT1A); se ha descrito que el origen de la duplicación es el intercambio desigual de las cromátidas durante la meiosis entre dos regiones de 24 kb denominadas sitios REPCMT1A, encontrándose un REP proximal y un REP distal, los cuales tienen una homología de 98%. Dentro de cada uno de estos sitios existen zonas denominadas puntos calientes de mutación (hot spot), donde se presenta el mayor número de variantes y mutaciones que pudieran dar origen al intercambio desigual. El objetivo de este trabajo fue diseñar un conjunto de microsondas para elaborar un microarreglo con el cual pueda detectarse la presencia de variantes y puntos de mutación en los sitios REP-proximal y REP-distal CMT1A. Material y métodos A partir de las secuencias informadas de los REP distal y proximal, se delimitaron los sitios hot spot dentro de las regiones proximal y distal. Estas secuencias se alinearon, se empalmaron y se detectaron 12 zonas de diferencia secuencial. Resultados y conclusiones. Se diseñaron y analizaron 24 microsondas mediante el programa Genosensor Probe Designer. Las sondas podrán ser sintetizadas y utilizadas en un microarreglo que permita encontrar variaciones, puntos de mutación, y facilitar el diagnóstico de pacientes con CMT1A.

BACKGROUND: Gene PMP22 is duplicated in patients with CMT1A. Duplication is due to an unequal chromatid interchange during meiosis that takes place between two 24 Kb regions named REP-CMT1A proximal and distal sites. Homology is approximately 98%. Within each one of the sites we find zones termed hot spots where a greater number of variants and mutations could give origin to an unequal interchange. The aim of this study was to design a set of probes to create a microarray that could detect the presence of variants and mutation points in distal and proximal REP sites among patients with CMT1A. MATERIAL AND METHODS: With reported sequences of distal and proximal REPs, we determined hot spot sites within proximal and distal regions. These sequences were aligned and matched, hence 12 zones were detected. RESULTS AND CONCLUSIONS: Twenty four probes were designed and analyzed using the Genosensor Probe Designer program. Probes could be synthesized and used in a microarray that is able to find variations and mutation points and facilitates diagnosis of patients with CMT1A.

Evaluación de la biopsia percutánea en el diagnóstico del síndrome de destrucción vertebral tóracico y lumbar / Percutaneous biopsy evaluation in the diagnosis of thoracic and lumbar vertebral destruction syndrome

BACKGROUND: The vertebral destruction syndrome is defined as those pathologies affecting the integrity of the vertebral structure, modifying its normal architecture and resulting in neurological deficit. Correct diagnosis is essential to define appropriate treatment. Biopsy, in addition to histopathological study, is a vital element for definitive diagnosis. METHODS: We carried out a descriptive, deliberate interventional study in 20 patients with a diagnosis of vertebral destruction in whom a percutaneous transpendicular biopsy was done between January 2005 and July 2006. Variables analyzed were age, sex, affected segment, neurological condition, neurological deficit type, results of the biopsy and specific diagnosis. RESULTS: There was a predominance of males (55%). The lumbar spine was the most affected region in 80% of patients. Of the biopsies performed, 10% were reported as normal tissue, 20% with degenerative changes, 15% with inflammatory changes, 15% with primary tumoral lesion, 5% with chronic osteomyelitis, 10% with tuberculosis, 15% with tumoral metastasis and 10% necrotic devitalized bone tissue. Of these patients, 55% were treated nonsurgically, and the remaining 45% were treated surgically. No complications were reported. CONCLUSIONS: Percutaneous transpedicular biopsy has only 55% specificity in diagnosis and for that reason is a less useful diagnostic method in our setting for destructive lesion diagnosis from the vertebral body.

Estrategias para el diagnóstico clinico y molecular de Charcot-Marie-Tooth 1A: estudio en pacientes mexicanos / Strategies for clinical and molecular diagnosis of Charcot-Marie-Tooth 1A among Mexican patients

Antecedentes: La neuropatía periférica de Charcot-Marie-Tooth (CMT) es la enfermedad hereditaria más común del sistema nervioso periférico humano. El subtipo más frecuente, CMT1A, es asociado a una duplicación de un fragmento de ~1.5 Mb en 17p11.2-p12, que incluye al gen PMP22. Objetivo: Describir diferentes estrategias para el diagnóstico clínico y molecular de CMT1A en pacientes del Instituto Nacional de Rehabilitación. Material y métodos: A 17 pacientes estudiados clínica y electrofisiológicamente que reunieron los criterios para CMT1, se les realizó el estudio molecular mediante electroforesis capilar para detectar la duplicación del gen PMP22. Resultados: Los estudios clínico, bioquímico y electrofisiológico ofrecieron los criterios para establecer el diagnóstico de CMT1. Con la electroforesis capilar se detectó la duplicación del gen PMP22 en siete pacientes que fueron diagnosticados clínica y electrofisiológicamente como CMT1, pudiendo llegar al diagnóstico de CMT1A. Todas las duplicaciones identificadas fueron corroboradas mediante hibridación in situ fluorescente. Conclusión: Los resultados nos permiten asegurar que la electroforesis capilar es un método fácil y confiable para detectar la duplicación del gen PMP22. Además, el aplicar diferentes estrategias tanto clínicas, electrofisiológicas y moleculares en este tipo de pacientes, nos permitieron establecer el diagnóstico correcto y ofrecer asesoramiento genético adecuado.

BACKGROUND: Charcot-Marie-Tooth (CMT) is the most common inherited disorder of the human peripheral nerve. The mos tfrequent subtype, CMT1A, is associated with duplication of approximately 1.5 Mb fragment in 17p11-p12, that includes the PMP22 gene. OBJECTIVE: The aim of this study was to describe different strategies used for clinical and molecular CNT1A diagnoses among patients attending the National Rehabilitation Institute of Mexico (INR). MATERIAL AND METHODS: 17 patients had clinical and electrophysiological features compatible with CMT1. A molecular study using capillary electrophoresis (CE) was performed and a PMP22 gene duplication was detected RESULTS: Clinical, biochemical and electrophysiological studies constituted the inclusion criteria to establish a CMT1 diagnosis. With CE the duplication of the PMP22 gene was observable and we established a possible CMT1A diagnosis in seven patients. All duplications detected by capillary electrophoresis were corroborated using FISH. CONCLUSION: CE is a feasible and reliable method to detect PMP22 gene duplication. Using different clinical, electrophysiological and molecular strategies in this patient population allowed us to establish an accurate diagnosis and offer suitable genetic counseling.

[Use of fibrin glue in combination with autologous bone graft as bone enhancer in posterolateral spinal fusion. An experimental study in New Zealand rabbits]. / Liofilizado de fibrina combinado con injerto óseo autólogo en artrodesis posterolateral. Estudio en conejos de Nueva Zelanda.

BACKGROUND: Currently there are different strategies to increase the fusion rate in spine surgery in the presence of autologous bone graft. The use of fibrin glue has multiple applications in surgery, but there is controversy about the use of fibrin glue as a bone enhancer. METHODS: The purpose of the study was to determinate the effectiveness of fibrin glue as a bone enhancer in posterolateral arthrodesis in New Zealand rabbits. Posterolateral arthrodesis was done in ten New Zealand rabbits at the level of L5-L6 using autologous bone graft in the right side (control side) and autologous bone graft plus fibrin glue in the left side (study side). The rabbits were harvested at 8 weeks, obtaining the lumbar spine for radiological, manual palpation and light microscopic analysis. RESULTS: Solid arthrodesis was obtained in 100% of the controls and in only 60% of the study animals. There were no differences among methods for determination of solid arthrodesis whether by radiological, manual palpation or light microscopic analysis. In 40% of non-unions, only in one (10%) was fibrocartilage obtained. In the remaining 30%, only inflammatory cells were obtained in the gap between the transverse process. CONCLUSIONS: Fibrin glue does not have a positive effect in the success of solid fusion in posterolateral arthrodesis in rabbits. The use of fibrin glue significantly decreased the rate of solid fusion; therefore, we do not recommend its use as a bone enhancer.

[Surgical treatment for scoliosis. Minimal evolution control at 5 years]. / Tratamiento quirúrgico de la escoliosis. Control de evolución mínimo de 5 años.

BACKGROUND: We undertook this study to determine the surgical treatments results performed often to correct scoliosis in the Spinal Surgery Service in the INR/Orthopedics (National Institute of Rehabilitation/Orthopedics), Mexico City. METHODS: We conducted a longitudinal, prospective, descriptive, and clinical study with a deliberated intervention controlled from a historical cohort. One hundred twenty patients with scoliosis were reviewed in whom surgery was performed during 1990-1999. For quantitative variables, pre- vs. postoperative measures were compared using non-parametric means with chi(2) or in this case with ANOVA by Kruskall-Wallis test. Differences are considered significant if p <0.05. RESULTS: Age average of patients was 12 years. There were 75 females and 45 males. There were 59 idiopathic scoliosis cases and 54 congenital scoliosis cases. Anterior approach was accomplished in 61 cases with posterior fixation. Posterior approach was used in 54 cases. There were 76 cases of Luque segmental instrumentation. Pre-operatively, scoliosis was ranked (18 to 110 grades) and postoperatively (5 to 90 grades) (p = 0.00001). There were 21 complications, 9 due to injuries or infection. In 76 patients, different fixation techniques were used, obtaining a correction average of 14.47 grades. Forty four patients were structured with bars, four distal screws, two compression screws, proximal hooks with sublaminar wire, and the angle was reduced on average 23.11 grades. CONCLUSIONS. Average reduction of scoliosis was higher with the modified Luque III instrumentation (p <0.045). There was no difference between etiology and preoperative angle.

Oral pathology in a group of Mexican patients with genetic diseases.

UNLABELLED: Without considering infectious and traumatic diseases, the great majority of oral cavity diseases have a genetic base, in some cases identifiable, in others not. For the stomatologists it is of great importance to know the clinical characteristics and type of alteration that go with genetic etiology syndromes to be able to offer patients an adequate multidisciplinary treatment. OBJECTIVE: Intentional search and description of oral pathology in patients with diverse genetic diseases. STUDY DESIGN: An observational and descriptive 4 month study of 62 patients from the Genetics Department of the National Institute of Rehabilitation, was done. Taken into consideration, aside from oral manifestations and genetic disease, were age, sex, consanguinity and inbreeding. The majority of patients who have genetic pathology do not have curative treatment, but they can receive other treatments to improve their quality of life, among these are dental treatments. RESULTS: The more common diseases we found were hereditary peripheral neuropathies, skeletal dysplasias, limb malformation and muscular dystrophies. Diverse features were described, registered and grouped according to their location. CONCLUSIONS: Presently it is important to look for the genetic etiology of all diseases to seek specific treatments and prevent them. This will change the practice of medicine and dentistry.

[Percutaneous biopsy evaluation in the diagnosis of thoracic and lumbar vertebral destruction syndrome]. / Evaluación de la biopsia percutánea en el diagnóstico del síndrome de destrucción vertebral tóracico y lumbar.

BACKGROUND: The vertebral destruction syndrome is defined as those pathologies affecting the integrity of the vertebral structure, modifying its normal architecture and resulting in neurological deficit. Correct diagnosis is essential to define appropriate treatment. Biopsy, in addition to histopathological study, is a vital element for definitive diagnosis. METHODS: We carried out a descriptive, deliberate interventional study in 20 patients with a diagnosis of vertebral destruction in whom a percutaneous transpendicular biopsy was done between January 2005 and July 2006. Variables analyzed were age, sex, affected segment, neurological condition, neurological deficit type, results of the biopsy and specific diagnosis. RESULTS: There was a predominance of males (55%). The lumbar spine was the most affected region in 80% of patients. Of the biopsies performed, 10% were reported as normal tissue, 20% with degenerative changes, 15% with inflammatory changes, 15% with primary tumoral lesion, 5% with chronic osteomyelitis, 10% with tuberculosis, 15% with tumoral metastasis and 10% necrotic devitalized bone tissue. Of these patients, 55% were treated nonsurgically, and the remaining 45% were treated surgically. No complications were reported. CONCLUSIONS: Percutaneous transpedicular biopsy has only 55% specificity in diagnosis and for that reason is a less useful diagnostic method in our setting for destructive lesion diagnosis from the vertebral body.

[Strategies for clinical and molecular diagnosis of Charcot-Marie-Tooth 1A among Mexican patients]. / Estrategias para el diagnóstico clinico y molecular de Charcot-Marie-Tooth 1A. Estudio en pacientes mexicanos.

BACKGROUND: Charcot-Marie-Tooth (CMT) is the most common inherited disorder of the human peripheral nerve. The mos tfrequent subtype, CMT1A, is associated with duplication of approximately 1.5 Mb fragment in 17p11-p12, that includes the PMP22 gene. OBJECTIVE: The aim of this study was to describe different strategies used for clinical and molecular CNT1A diagnoses among patients attending the National Rehabilitation Institute of Mexico (INR). MATERIAL AND METHODS: 17 patients had clinical and electrophysiological features compatible with CMT1. A molecular study using capillary electrophoresis (CE) was performed and a PMP22 gene duplication was detected RESULTS: Clinical, biochemical and electrophysiological studies constituted the inclusion criteria to establish a CMT1 diagnosis. With CE the duplication of the PMP22 gene was observable and we established a possible CMT1A diagnosis in seven patients. All duplications detected by capillary electrophoresis were corroborated using FISH. CONCLUSION: CE is a feasible and reliable method to detect PMP22 gene duplication. Using different clinical, electrophysiological and molecular strategies in this patient population allowed us to establish an accurate diagnosis and offer suitable genetic counseling.

Cockayne's syndrome: a case report. Literature review.

Cockayne s syndrome is a genetic disorder with a recessive autosomal inheritance, described first by Cockayne in 1936. Patients with this syndrome present failure to thrive, short stature, premature aging, neurological alterations, photosensitivity, delayed eruption of the primary teeth, congenitally absent of some permanent teeth, partial macrodontia, atrophy of the alveolar process and caries. It could be caused by two gene mutations, CNK1 (ERCC8) and ERCC6, located on the 5 and 10 chromosomes respectively, causing two variations of Cockayne s syndrome, CS-A, secondary to a ERCC8 mutation and CS-B with ERCC6 mutation, the last one causes hypersensitivity to the ultraviolet light secondary to a DNA repair defect. The syndrome is also associated with mutations of the XPB, XPD and XPG genes. In this report we present a 9 year and 4 month old patient. He had a height of 94 cm, weight of 8.6 Kg, head circumference of 42 cm. and blood pressure of 120/80. Cachectic habitus, kyphosis, microcephaly, oval face, sunken eyes, a thin and beaklike nose, lack of subcutaneous facial fat (especially in the middle of the face), and large ears give the patient a birdlike appearance. It is notorious the photosensitivity in all the sun-exposed skin. The patient also displays delayed psychomotor skills and mental retardation. In the oral cavity we found deficient hygiene, gingivitis, cervical caries, enamel hipoplasia, abnormal position of the upper and inferior lateral incisors, macrodontia of the upper central teeth, the left one presented a caries. In the x-ray we observed congenital absence of 14, 23 and 24 teeth and mandibular hipoplasia. The aim of this review is to show the dentistry community the characteristics of the Cockayne s syndrome by means of a clinical case.