Abstract The spinocerebellar ataxia type 2 is a neurodegenerative disease with autosomal dominant inheritance; clinically characterized by progressive cerebellar ataxia, slow ocular saccades, nystagmus, ophthalmoplegia, dysarthria, dysphagia, cognitive deterioration, mild dementia, peripheral neuropathy. Infantile onset is a rare presentation that only has been reported in four instances in the literature. In the present work a boy aged 5 years 7 months was studied due to horizontal gaze-evoked nystagmus, without saccades, ataxic gait, dysarthria, dysphagia, dysmetria, generalized spasticity mainly pelvic, bilateral Babinsky. The mother aged 27 years-old presented progressive cerebellar ataxia, dysarthria, dysmetria, dysdiadochokinesis, limb ataxia and olivopontocerebellar atrophy. The molecular analysis was made by identifying the expansion repeats in tandem by long PCR to analyze the repeats in the ATXN2 gene. We found an extreme CAG expansion repeats of ~884 repeats in the child. We describe a Mexican child affected by SCA2 with an infantile onset, associated with a high number of CAG repeats previously no reported and anticipation phenomenon.

Abstract The ataxin 2 gene is a target in the pathogenesis of complex diseases, including cardiovascular risk factors and neurodegenerative diseases. ATXN2 gen has VNTR in exon 1, whose expansion exceeding 30 repetitions leads to the development of spinocerebellar ataxia type 2; lower-range repetitions are associated with type 2 diabetes or amyotrophic lateral sclerosis. This locus is also linked with metabolic and inflammatory phenotypes. In conclusion, this gene can be used as a clinical marker of metabolic and neurological phenotypes, which is related to its pleiotropic effect.

Resumen El gen de la ataxina-2 es un blanco en la patogénesis de enfermedades complejas, entre ellas los factores de riesgo cardiovascular y enfermedades neurodegenerativas. El gen ATXN2 tiene un VNTR en el exón 1, cuya expansión por encima de las 30 repeticiones provoca al desarrollo de ataxia espinocerebelosa tipo 2; las repeticiones en rango menor se asocian con diabetes tipo 2 o esclerosis lateral amiotrófica. También este locus está ligado con fenotipos metabólicos e inflamatorios. En conclusión, el gen puede ser utilizado como marcador clínico de fenotipos metabólicos y neurológicos, lo cual está relacionado con su efecto pleiotrópico.

The non-syndromic anterior cervical hypertrichosis (OMIM N° 600457) is a genetic disorder characterized by a patch of hair at the level of the laryngeal prominence. We present a 12-year-old boy with anterior cervical hypertrichosis and mild generalized hypertrichosis. He has no neurological, ophthalmological or skeletal anomalies. The clinical follow up is 10 years.

La hipertricosis cervical anterior no sindrómica (OMIM N° 600457) es un desorden genético caracterizado por un parche de pelo a nivel de la prominencia laríngea. Se presenta a un niño de 12 años de edad con hipertricosis cervical anterior e hipertricosis generalizada leve, sin alteraciones neurológicas, oftalmológicas ni esqueléticas, en seguimiento clínico por un lapso de 10 años.

OBJETIVO: Elaboramos este estudo para avaliar se o polimorfismo -675 4G/5G no gene inibidor 1 do ativador do plasminogênio se associa à obesidade e à resistência insulínica em crianças mexicanas. MÉTODOS: Foi realizado um estudo transversal em 174 crianças, 89 delas com peso normal e 85 obesas, variando sua idade de 6 a 13 anos. Todas as crianças eram do estado de Guerrero e foram recrutadas de três escolas primárias na cidade de Chilpancingo, México. Os níveis de insulina foram determinados por prova imunoenzimática. Foi usado o modelo de avaliação da homeostase para determinar resistência insulínica. O polimorfismo -675 4G/5G no gene PAI-1 foi analisado pelo método reação de polimerase em cadeia-polimorfismo no comprimento dos fragmentos de restrição. RESULTADOS: A prevalência de resistência insulínica no grupo obeso foi mais alta (49,41%) do que no grupo com peso normal (16,85%). O polimorfismo 4G/5G do PAI-1 foi encontrado em equilíbrio de Hardy Weinberg. O genótipo 4G/5G contribuiu para um aumento significativo da relação cintura-quadril (β = 0,02, p = 0,006), da circunferência da cintura (β = 4,42, p = 0,009) e da espessura da prega subescapular (β = 1,79, p = 0,04), mas não se relacionou com a resistência insulínica. CONCLUSÃO: O genótipo -675 4G/5G do gene PAI-1 se associou a aumento da adiposidade corporal em crianças mexicanas.

OBJECTIVE: To assess whether the -675 4G/5G polymorphism in the plasminogen activator inhibitor-1 gene is associated with obesity and insulin resistance in Mexican children. METHODS: A cross-sectional study was performed in 174 children, 89 with normal-weight and 85 with obesity, aged from 6 to 13 years. All children were from state of Guerrero, and recruited from three primary schools in the city of Chilpancingo, Mexico. Insulin levels were determined by immunoenzymatic assay. The homeostasis model assessment was used to determine insulin resistance. The -675 4G/5G polymorphism in PAI-1 gene was analyzed by polymerase chain reaction-restriction fragment length polymorphism. RESULTS: The prevalence of insulin resistance in the obese group was higher (49.41%) than in the normal-weight group (16.85%). The 4G/5G PAI-1 polymorphism was found in Hardy Weinberg equilibrium. The 4G/5G genotype contributed to a significant increase in waist-hip ratio (β = 0.02, p = 0.006), waist circumference (β = 4.42, p = 0.009), and subscapular skinfold thickness (β = 1.79, p = 0.04); however, it was not related with insulin resistance. CONCLUSION: The -675 4G/5G genotype of PAI-1 gene was associated with increase of body adiposity in Mexican children.

This study compares the detection of Mycobacterium tuberculosis through bacilloscopy (Ziehl-Neelsen stain), growth in Lowenstein-Jensen medium, and polymerase chain reaction (PCR) carried out with DNA taken directly from various types of samples. A total of 252 samples were analyzed (114 sputum, 96 urine, 15 cerebrospinal fluid, and 27 of other types) from 160 patients with any form of suspected tuberculosis who came to the Clinical Pathology Laboratory of the Specialties Hospital of the Western National Medical Center of the Mexican Social Security Institute. In all cases Ziehl-Neelsen stains were done, as were also cultures with Lowenstein-Jensen medium and PCR amplification of a segment of 285 base pairs specific to the M. tuberculosis complex. Of the 252 samples, with the culture, 18 were positive for nontuberculous mycobacteria. Of the 234 others, 12 (5.1%) were positive with the PCR and the culture, 174 (74.4%) negative in both tests, 47 (20.1%) positive with the PCR and negative with the culture, and 1 (0.4%) negative with the PCR and positive with the culture. Using the culture as the reference test, the PCR provided a sensitivity of 92.3%, a specificity of 78.7%, a positive predictive value of 20.3%, and a negative predictive value of 99.4%. The PCR detection limit with DNA taken from culture was 10 fg, equivalent to four or five mycobacteria. Also in comparison with the culture, the PCR correctly identified the totality of the mycobacteria of the M. tuberculosis complex. Taking the culture as the reference test, when analyzing just the sputum samples, the direct PCR provided a sensitivity of 90.9%, a specificity of 89.5%, a positive predictive value of 52.6%, and a negative predictive value of 98.7%. The PCR is a sensitive and specific technique for detecting the M. tuberculosis complex in both positive and negative bacilloscopy samples. A controlled PCR procedure makes it possible to establish or to exclude the diagnosis of tuberculosis in a time that is reduced from more than three weeks to just 24 to 48 hours. This is particularly useful when an early diagnosis is needed to establish a patient's prognosis or in organ transplant cases.

Este estudio compara la detección de Mycobacterium tuberculosis mediante baciloscopia (tinción de Ziehl-Neelsen), cultivo en medio de Löwenstein-Jensen y reacción en cadena de la polimerasa (RCP) realizada con ADN extraído directamente de distintos tipos de muestras. Se analizaron 252 muestras (114 de esputo, 96 de orina, 15 de LCR y 27 de otros tipos) de 160 pacientes con sospecha de tuberculosis en cualquiera de sus formas que acudieron al Laboratorio de Patología Clínica del Hospital de Especialidades del Centro Médico Nacional de Occidente del Instituto Mexicano del Seguro Social. En todos los casos se realizó tinción de Ziehl-Neelsen, cultivo en medio de Löwenstein-Jensen y amplificación por RCP de un segmento de 285 pares de bases específico del complejo M. tuberculosis. De las 252 muestras, 18 fueron positivas para micobacterias no tuberculosas en el cultivo. De las 234 restantes, 12 (5,1%) fueron positivas en la RCP y el cultivo, 174 (74,4%) negativas en ambas pruebas, 47 (20,1%) positivas en la RCP y negativas en el cultivo y 1 (0,4%) negativa en la RCP y positiva en el cultivo; tomando el cultivo como prueba de referencia, la RCP proporcionó una sensibilidad de 92,3%, una especificidad de 78,7%, un valor predictivo positivo de 20,3% y un valor predictivo negativo de 99,4%. El límite de detección de la RCP en ADN extraído de cultivo fue de 10 fg (equivalente a 4 ó 5 micobacterias). También en comparación con el cultivo, la RCP identificó correctamente a la totalidad de las micobacterias del complejo M. tuberculosis. Tomando como prueba de referencia el cultivo, al analizar únicamente las muestras de esputo, la RCP directa proporcionó una sensibilidad de 90,9%, una especificidad de 89,5%, un valor predictivo positivo de 52,6% y un valor predictivo negativo de 98,7%. La RCP es una técnica sensible y específica para detectar el complejo M. tuberculosis en muestras tanto positivas como negativas en la baciloscopia. Un procedimiento controlado de RCP permite establecer o excluir el diagnóstico de tuberculosis en un tiempo que se reduce de más de tres semanas a tan solo 24 a 48 horas, lo cual resulta particularmente útil cuando es necesario un diagnóstico temprano para establecer el pronóstico del paciente o en casos de transplante de órganos.