Mutational spectrum and genotype-phenotype correlation in Mexican patients with infantile-onset and late-onset Pompe disease.

BACKGROUND: Pompe Disease (PD) is a metabolic myopathy caused by variants in the GAA gene, resulting in deficient enzymatic activity. We aimed to characterize the clinical features and related genetic variants in a series of Mexican patients. METHODS: We performed a retrospective study of clinical records of patients diagnosed with LOPD, IOPD or pseudodeficiency. RESULTS: Twenty-nine patients were included in the study, comprising these three forms. Overall, age of symptom onset was 0.1 to 43 years old. The most frequent variant identified was c.-32-13T>G, which was detected in 14 alleles. Among the 23 different variants identified in the GAA gene, 14 were classified as pathogenic, 5 were likely pathogenic, and 1 was a variant of uncertain significance. Two variants were inherited in cis arrangement and 2 were pseudodeficiency-related benign alleles. We identified two novel variants (c.1615 G>A and c.1076-20_1076-4delAAGTCGGCGTTGGCCTG). CONCLUSION: To the best of our knowledge, this series represent the largest phenotypic and genotypic characterization of patients with PD in Mexico. Patients within our series exhibited a combination of LOPD and IOPD associated variants, which may be related to genetic diversity within Mexican population. Further population-wide studies are required to better characterize the incidence of this disease in Mexican population.

IFITM5-related (type V) osteogenesis imperfecta with evidence of perinatal involvement: A case report.

Osteogenesis imperfecta (OI) is a rare hereditary disorder characterized by bone fragility and frequent fractures. While most cases are attributed to variations in collagen-coding genes COL1A1 and COL1A2, other genes such as IFITM5 have also been associated with the disease, accounting for up to 5 % of cases. Here, we report a case of a 3-month-old female with a femur fracture and limb deformity. X-rays revealed evidence of osteopenia and previous fractures in the arms, clavicle, ribs, and left limb, alongside prenatal bone deformities detected by ultrasound. Initial clinical evaluation suggested progressively deforming (Sillence's type III) osteogenesis imperfecta (OI). Molecular testing led to the diagnosis of IFITM5-related OI, identifying the c.-14C>T (rs587776916) variant. Although this variant has been previously reported in patients with IFITM5-related OI, prenatal involvement had not been associated with this variant.

Infantile-onset Pompe disease in seven Mexican children.

INTRODUCTION: Pompe disease (PD) is a rare form of metabolic myopathy; the classic infantile presentation is severe, with death occurring before reaching one year of life, and the non-classical form is of slower progression and survival can exceed one year. OBJECTIVE: To describe the genotype and characteristics of Mexican patients with infantile-onset PD. METHODS: Seven patients with PD confirmed by enzymatic activity determination and GAA gene molecular analysis were included. Mutations were reviewed in genomic databases. RESULTS: Median age at symptom onset was four months (1-12 months) and age at diagnosis was eight months (4-16 months). All patients had cardiomyopathy: four who died before one year of age had mutations that predicted severe disease (c.2431dup, c.2560C>T, c.655G>A, c.1987delC) and were negative for cross-reactive immunologic material (CRIM). Three patients survived after one year of age with enzyme replacement therapy; one survived almost five years, another 18 months, and one girl was almost three years of age at the time of this report; their pathogenic variants predicted potentially less severe disease (c.1979G>A, c.655G>A, c.1447G>A) and they were positive for CRIM. CONCLUSION: There was a good correlation between genotype and phenotype in children with Pompe disease.

INTRODUCCIÓN: La enfermedad de Pompe (EP) es una forma rara de miopatía metabólica; la presentación infantil clásica es severa y el fallecimiento acontece antes del año de vida, y la forma no clásica es de progresión más lenta y la sobrevivencia puede superar el año. OBJETIVO: Describir genotipo y características de pacientes mexicanos con EP de inicio infantil. MÉTODOS: Se incluyeron siete pacientes con enfermedad confirmada mediante actividad enzimática y estudio molecular del gen GAA. Se revisaron las mutaciones en bases de datos genómicas. RESULTADOS: La mediana de la edad de inicio de los síntomas fue de cuatro meses (1-12 meses) y la edad de diagnóstico fue de ocho meses (4-16 meses). Todos los pacientes tenían cardiomiopatía: cuatro que fallecieron antes del año presentaron mutaciones que predicen enfermedad severa (c.2431dup, c.2560C>T, c.655G>A, c.1987delC) y CRIM (cross-reactive immunologic material) negativo; tres sobrevivieron después del año de edad con terapia de reemplazo enzimático, uno casi cinco años, otro 18 meses y una niña tenía casi tres años al momento de este informe; sus variantes patogénicas predecían enfermedad potencialmente menos severa (c.1979G>A, c.655G>A, c.1447G>A) y CRIM positivo. CONCLUSIÓN: Existió buena correlación entre genotipo y fenotipo en niños con enfermedad de Pompe.

Enfermedad de Pompe de inicio infantil en siete niños mexicanos / Infantile-onset Pompe disease in seven Mexican children

Resumen Introducción: La enfermedad de Pompe (EP) es una forma rara de miopatía metabólica; la presentación infantil clásica es severa y el fallecimiento acontece antes del año de vida, y la forma no clásica es de progresión más lenta y la sobrevivencia puede superar el año. Objetivo: Describir genotipo y características de pacientes mexicanos con EP de inicio infantil. Métodos: Se incluyeron siete pacientes con enfermedad confirmada mediante actividad enzimática y estudio molecular del gen GAA. Se revisaron las mutaciones en bases de datos genómicas. Resultados: La mediana de la edad de inicio de los síntomas fue de cuatro meses (1-12 meses) y la edad de diagnóstico fue de ocho meses (4-16 meses). Todos los pacientes tenían cardiomiopatía: cuatro que fallecieron antes del año presentaron mutaciones que predicen enfermedad severa (c.2431dup, c.2560C>T, c.655G>A, c.1987delC) y CRIM (cross-reactive immunologic material) negativo; tres sobrevivieron después del año de edad con terapia de reemplazo enzimático, uno casi cinco años, otro 18 meses y una niña tenía casi tres años al momento de este informe; sus variantes patogénicas predecían enfermedad potencialmente menos severa (c.1979G>A, c.655G>A, c.1447G>A) y CRIM positivo. Conclusión: Existió buena correlación entre genotipo y fenotipo en niños con enfermedad de Pompe.

Abstract Introduction: Pompe disease (PD) is a rare form of metabolic myopathy; the classic infantile presentation is severe, with death occurring before reaching one year of life, and the non-classical form is of slower progression and survival can exceed one year. Objective: To describe the genotype and characteristics of Mexican patients with infantile-onset PD. Methods: Seven patients with PD confirmed by enzymatic activity determination and GAA gene molecular analysis were included. Mutations were reviewed in genomic databases. Results: Median age at symptom onset was four months (1-12 months) and age at diagnosis was eight months (4-16 months). All patients had cardiomyopathy: four who died before one year of age had mutations that predicted severe disease (c.2431dup, c.2560C>T, c.655G>A, c.1987delC) and were negative for cross-reactive immunologic material (CRIM). Three patients survived after one year of age with enzyme replacement therapy; one survived almost five years, another 18 months, and one girl was almost three years of age at the time of this report; their pathogenic variants predicted potentially less severe disease (c.1979G>A, c.655G>A, c.1447G>A) and they were positive for CRIM. Conclusion: There was a good correlation between genotype and phenotype in children with Pompe disease.

Stem-cell transplantation for children with primary immune deficiencies: A retrospective study of 19 patients from one centre in Mexico.

INTRODUCTION: For many patients with primary immune deficiency (PID), stem-cell transplantation (SCT) may be life-saving. OBJECTIVE: To review our experience of 11 years transplanting children with PID in Mexico. METHODS: Chart review of patients who underwent SCT from 2008 to 2018, to describe their diagnoses, time to transplant, conditioning regime, survival rate and outcomes. All patients received post-transplant cyclophosphamide as graft-versus-host-disease (GVHD) prophylaxis. RESULTS: 19 patients with combined, phagocytic or syndromic PID from 5 states. Twelve of them were male (58%) and 14 survive (79%). Mean age at HSCT was 41.9 months; mean time from diagnosis was 31.2 months. Seven grafts were umbilical cord and 12 haploidentical. The conditioning regime was myeloablative, with five primary graft failures. Two patients had partial and 10 full chimerism. Five patients died within 2 months after transplant. Immune reconstitution was complete in 11 of 19 patients. We found a prevalence of 21% GVHD. DISCUSSION: We describe 19 patients from Mexico with 8 PID diagnoses who underwent allogenic HSCT over a period of 11 years. Survival rate and other outcomes compare well with industrialized countries. We recommend the use of post-transplant cyclophosphamide to prevent GVHD in scenarios of resource scarcity and a lack of HLA-identical donors.

Anesthetic complications in children with mucopolysaccharidosis / Complicaciones anestésicas en niños con mucopolisacaridosis

Abstract: Introduction: A high percentage of mucopolysaccharidosis patients require surgery at some point. Common features like respiratory limitations and cardiovascular disease pose a high anesthetic risk. We describe the prevalence of anesthetic complications in our institution. Material and methods: Patients' medical history and reported surgery data from 18 eligible records were reviewed from a total of 29 mucopolysaccharidosis diagnosed children registered between the years 1999 to 2019 at a hospital in Mexico. Results: Median age was 11 years. 12 patients were type I, two type II, three type IV, and one type VI. Intravenous premedication was administered in 69.5% and induction was intravenous in 91.3% of the surgical procedures. Orotracheal intubation was the first attempted anesthetic method in 47.8% and a laryngeal mask in another 47.8%. Bronchospasm was the most frequent complication in 17.4% followed by difficult intubation in 13.1%. Conclusions: Bronchospasm was the most prevalent complication. A higher Cormack-Lehane grade was primarily related. The most prevalent concomitant risk factors were short neck and restrictive chest rendering airway management difficult in comparison to the general population.

Resumen: Introducción: Un alto porcentaje de pacientes con mucopolisacaridosis requieren cirugía en algún momento. Algunas características comunes como alteraciones respiratorias y enfermedades cardiovasculares constituyen un alto riesgo anestésico. Describimos la prevalencia de las complicaciones anestésicas en nuestra institución. Material y métodos: Fueron revisados los antecedentes y los datos quirúrgicos de 18 pacientes elegibles, extraídos de un total de 29 expedientes de niños con mucopolisacaridosis registrados entre los años 1999 y 2019 en un hospital de México. Resultados: La mediana de edad fue de 11 años. Doce pacientes fueron de tipo I, dos tipo II, tres tipo IV y uno tipo VI. La premedicación intravenosa se administró en 69.5% y la inducción fue intravenosa en 91.3% de los procedimientos quirúrgicos. El primer método anestésico intentado fue la intubación orotraqueal en 47.8% y la máscara laríngea en 47.8%. El broncoespasmo fue la complicación más frecuente en 17.4%, seguida de una intubación difícil en 13.1%. Conclusiones: El broncoespasmo fue la complicación más observada relacionada, primordialmente, con un grado Cormack-Lehane más alto. Los factores de riesgo concomitantes más frecuentes fueron el cuello corto y las restricciones torácicas, lo que dificulta en mayor grado el manejo de las vías respiratorias en comparación con la población general.

Case Report: DOCK8 Deficiency Without Hyper-IgE in a Child With a Large Deletion.

Autosomal recessive (AR) DOCK8 deficiency is a well-known actinopathy, a combined primary immune deficiency with impaired actin polymerization that results in altered cell mobility and immune synapse. DOCK8-deficient patients present early in life with eczema, viral cutaneous infections, chronic mucocutaneous candidiasis, bacterial pneumonia, and abscesses, together with eosinophilia, thrombocytosis, lymphopenia, and variable dysgammaglobulinemia that usually includes Hyper-IgE. In fact, before its genetic etiology was known, patients were described as having a form of Hyper-IgE syndrome, a name now deprecated in favor of genetic defects. We describe a school-age male patient with a clinical picture suggestive of DOCK8 deficiency, except for high serum IgE or a family history: early onset, failure to thrive, eczema, warts, condyloma, bronchiolitis, pneumonia, recurrent otitis media, bronchiectasis, candidiasis, leukocytosis, eosinophilia, high IgA, low IgG, and low CD4+ T cells. We were able to confirm the diagnosis through protein expression and whole-exome sequencing. We review the clinical, laboratory, and genetic features of 200 DOCK8-deficient patients; at least 4 other patients have had no elevated IgE, and about 40% do not have Hyper-IgE (above 1,000 IU/mL). Despite this, the constellation of signs, symptoms, and findings allow the suspicion of DOCK8 deficiency and other actinopathies.

COVID-19 in the Context of Inborn Errors of Immunity: a Case Series of 31 Patients from Mexico.

INTRODUCTION: Patients with inborn errors of immunity (IEI) have a compromised or inappropriate immune response. Although they might be considered a high-risk group for severe SARS-CoV-2 infection, the reported impact of COVID-19 in these patients has been reassuring, while the differential susceptibility of distinct types of IEI remains unclear. OBJECTIVE: We aimed to describe the findings and outcomes of our known patients with IEI who were diagnosed with COVID-19. METHODS: In a retrospective study from March 2020 to February 2021, four centers in Mexico collected clinical, laboratory, and genetic data from pediatric and adult patients with known diagnoses of IEI who presented with COVID-19, based on compatible symptoms and positive SARS-CoV-2 testing or known household exposure. RESULTS: We report 31 patients with known IEI from Mexico who presented with SARS-CoV-2 infection. Seventy-four percent were male, 52% were pediatric, and 81% survived. Their ages ranged from 5 months to 56 years, with a median of 17 years. Sixty-five percent had predominant antibody deficiencies, 48% were hospitalized, and 26% required ICU. Pediatric patients had a higher hospital admission rate than adults. Inpatient mortality was 40%, and ICU mortality rate was 63%. Forty-eight percent developed pneumonia, while 36% had evidence of hyperinflammation (4 adults and 7 children). Predominant laboratory features were lymphopenia and thrombocytopenia, seen in 70 and 44% of patients, respectively. The serum D-dimer median value was 2.6 (0.5-20.6) µg/mL, and the median highest ferritin value was 1015 (32-10,303) ng/mL. Intravenous immunoglobulin was used in 80% of patients. Other treatments included macrolides (39%) and corticosteroids (29%). Six patients died from secondary infection or uncontrolled systemic inflammation. DISCUSSION: Although impaired immunity due to IEI may be a predisposing factor for severe COVID-19, most of our patients with IEI who acquired the SARS-CoV-2 infection developed a well-tolerated infection and survived, as have more than 80% of worldwide reported patients to date. An impaired immune or inflammatory response may be a predisposing factor for some and a protective factor for others. A systematic review of the literature could help identify those patients at risk of severe disease and complications. Healthcare-associated infections should be aggressively prevented.

Attitude of the medical personnel of a pediatrics department towards patient death. / Actitud del personal médico de un servicio de pediatría ante la muerte de los pacientes.

Introduction: Tertiary care hospitals' physicians require high emotional competence, since they are faced with the demands of terminally ill patients and their families. Objective: to assess the attitude of physicians of a pediatrics department towards patient death. Method: Pediatrics staff and resident physicians anonymously answered the Attitudes Towards Death (ATD) questionnaire. Absolute frequencies, percentages, means, standard deviations, Student's t-test and the chi-square test were used. Statistical significance was considered with p < 0.05. Results: The questionnaire was answered by 38 physicians, 26 (68.4%) were residents and 12 (37.6%) staff physicians; 15 (39.4%) were males and 23 (60.6%) females. Four residents (15.4%) had a positive attitude versus 2 staff physicians (16.7%) (p = 0.920). Statistical significance was found in items 1 (69.2% of residents versus 100% of staff physicians, p = 0.03), 16 (23% of residents versus 100% of staff physicians, p = 0.001) and 19 (92.3% of residents versus 58.3% of staff physicians, p = 0.01), corresponding to the avoidance, acceptance and professional perspective dimensions. Conclusion: Less than 20% of pediatric physicians have a positive attitude towards death. Most didn't value death as a passage or transition to a better life, or as a solution to life's problems.

Introducción: Los médicos de hospitales de tercer nivel requie-ren alta competencia emocional, ya que enfrentan las de-mandas de enfermos terminales y sus fami-liares. Objetivo: Evaluar la actitud de médicos de un servicio de pediatría ante la muerte de los pacientes. Método: Médicos adscritos y residentes de pediatría contestaron anónimamente el Cuestionario de Actitudes ante la Muerte (CAM). Se utilizaron frecuencias absolutas, porcentajes, medias, desviaciones estándar, t de Student y chi cuadrado. Se consideró significación estadística con p < 0.05. Resultados: Contestaron el cuestionario 38 médicos, 26 (68.4 %) residentes y 12 (37.6 %) adscritos; 15 (39.4 %) hombres y 23 (60.6 %) mujeres. Cuatro residentes (15.4 %) tuvieron actitud positiva versus dos médicos adscritos (16.7 %) (p = 0.920). Se encontró significación estadística en los ítems 1 (69.2 % de residentes versus 100 % de adscritos, p = 0.03), 16 (23 % de residentes versus 100 % de adscritos, p = 0.001) y 19 (92.3 % de residentes versus 58.3 % de adscritos, p = 0.01), correspondientes a las dimensiones evitación, aceptación y perspectiva profesional. Conclusión: Menos de 20 % de los médicos de pediatría tiene una actitud positiva ante la muerte. La mayoría no valoró la muerte como un pasaje o tránsito hacia una vida mejor, ni como una salida a los problemas de la vida.

Multifocal Recurrent Osteomyelitis and Hemophagocytic Lymphohistiocytosis in a Boy with Partial Dominant IFN-γR1 Deficiency: Case Report and Review of the Literature.

Mutations in the genes coding for cytokines, receptors, second messengers, and transcription factors of interferon gamma (IFN-γ) immunity cause Mendelian susceptibility to mycobacterial disease (MSMD). We report the case of a 7-year-old male patient with partial dominant (PD) IFN-γ receptor 1 deficiency who had suffered from multifocal osteomyelitis attributable to bacille Calmette-Guérin vaccination since the age of 18 months. He developed hemophagocytic lymphohistiocytosis (HLH), a hyper-inflammatory complication, and died with multiorgan dysfunction, despite having been diagnosed and treated relatively early. Patients with PD IFN-γR1 deficiency usually have good prognosis and might respond to human recombinant subcutaneous IFN-γ. Several monogenic congenital defects have been linked to HLH, a catastrophic "cytokine storm" that is usually ascribed to lymphocyte dysfunction and thought to be triggered by interferon gamma. This is the sixth patient with both MSMD and HLH of whom we are aware. The fact that patients with macrophages that cannot respond to IFN-γ still develop HLH, bring these assumptions into question.

Alteraciones puberales en adolescentes con leucemia en fase de vigilancia.

OBJECTIVE: To evaluate which factors are associated with alterations in pubertal development in pediatric patients with leukemia in the surveillance phase. METHOD: A case-control study was carried out, including patients aged 8-14 years with diagnosis of acute lymphoblastic leukemia under surveillance. Demographic data were collected, age at diagnosis, type of leukemia, risk of leukemia, duration and type of treatment received, time of surveillance phase; and pubertal development was assessed by Tanner stage, bone age, pelvic ultrasound for women, and LH levels. Fisher's exact test and Mann-Whitney U-test were used. RESULTS: Twenty-five pediatric patients with a diagnosis of acute lymphoblastic leukemia between 8 and 14 years of age with a median of 8 were included, only 4 (16%) presented pubertal alterations, 1 had pubertal delay and 3 advanced puberty. The history of radiotherapy was related to pubertal alterations (p = 0.03). CONCLUSIONS: The antecedent of having received radiotherapy as part of the treatment in patients with acute lymphoblastic leukemia is a risk factor for developing pubertal abnormalities.

Zoledronate as effective treatment for minimal trauma fractures in a child with STAT3 deficiency and osteonecrosis of the hip.

Signal transducer and activator of transcription 3 (STAT3) deficiency is a primary immunodeficiency characterized by eczema, complicated recurrent infections, elevated serum immunoglobulin E (IgE), osteopenia, and minimal trauma fractures. Zoledronic acid (ZA) is a long-acting bisphosphonate that has been successfully used in children with secondary osteoporosis and osteogenesis imperfecta. We describe the case of a 7-year-old male with STAT3 deficiency and minimal trauma fractures, who also developed osteonecrosis of the hip. He responded well to intravenous ZA every 6 months for 18 months. Three years later, he walks independently and unaided, and has not suffered any other fractures. Although more studies are needed, ZA might help reduce minimal trauma fractures in patients with STAT3 deficiency.

[Clinical presentation of supratentorial and infratentorial intracranial tumors in pediatric patients]. / Presentación clínica de tumores intracraneales supratentoriales (ST) e infratentoriales (IT) en pacientes pediátricos.

BACKGROUND: Brain tumors are the second most common malignancy in childhood and they are also the most common solid tumors in children and the most frequent cause of morbidity and mortality associated with cancer in this age. OBJECTIVE: To determine the clinical presentation of supratentorial and infratentorial intracranial tumors in pediatric patients. MATERIAL AND METHODS: An observational, retrospective, cross-sectional comparative study in which records the clinical manifestations of 51 pediatric patients diagnosed with intracranial tumor, according with its location, supra- or infratentorial. RESULTS: 51 patients were analyzed. Tumor location was infratentorial in 32 patients (62.7%) and supratentorial in 19 (37.3%). Cerebellar syndrome occurred in 21 patients (65.6 %) with infratentorial tumor compared with six (31.5 %) with supratentorial tumor (p = 0.04; OR: 3.2; 95% CI: 1.1-12.8). Nystagmus was significantly more common in patients with infratentorial tumors (p = 0.029). Endocrine manifestations were present in four patients (21%) with supratentorial tumor and none of the infratentorial group (p = 0.03). CONCLUSIONS: Cerebellar syndrome was statistically significantly more common in patients with infratentorial when compared with patients with supratentorial. Nystagmus is one of the most common visual impairments in patients with infratentorial tumor. Endocrine disorders are significantly more frequent in patients with supratentorial tumor. The interval between onset of symptoms and diagnosis of intracranial tumor is significantly longer in children with supratentorial tumor because the symptoms are more insidious in onset and are mistaken for other benign conditions.

[Left ventricular adaptive response after surgery of aortic valve replacement for severe valvular stenosis]. / Respuesta adaptativa ventricular izquierda posterior a la cirugía de reemplazo valvular aórtico por estenosis valvular severa.

BACKGROUND: Myocardial hypertrophy is a compensatory mechanism in patients with severe aortic stenosis. The left ventricle fits the systolic pressure through a hypertrophic process with increased wall thickness. The effects of elevated ventricular afterload reduce ventricular myocardial elasticity and decrease coronary flow with increased myocardial work, oxygen consumption, and mortality. Aortic valve replacement surgery can cause regression of left ventricular hypertrophy and improve patient survival. The aim of this study was to evaluate left ventricular adaptive response after surgery of aortic valve replacement for severe valvular stenosis. MATERIAL AND METHODS: An observational, analytical, longitudinal study that included patients with diagnosis of aortic stenosis with evidence of left ventricular hypertrophy undergoing valve replacement during the period January 2013 to September 2014. Echocardiographic studies were performed before surgery and six months thereafter. Pre- and postoperative means were compared with Student t test for related samples. Statistical significance was considered at p ≤ 0.05. RESULTS: 24 patients were included, with an average age of 57.5 years, with no gender predominance, of which 87.5% had history of smoking and 50% with hypertension. There was no statistically significant difference in diastolic and systolic diameter before and after surgery. The interventricular septum was 14.9 ± 2.3 mm preoperative and 12.8 ± 2.2 mm postoperative (p = 0.001). The back wall was 14.2 ± 1.8 mm preoperative and 12.5 ± 2.2 mm postoperative (p = 0.002). The ventricular mass before surgery was 154.8 ± 54.3 g/m(2) and then 123.2 ± 41.4 g/m(2) (p = 0.000). The maximum preoperative transvalvular gradient was 93 ± 35 mmHg and postoperative was 32.2 ± 14.4 mmHg (p = 0.00). The average preoperative transvalvular gradient was 56.3 ± 19 mmHg and postoperative was 7.5 ± 16.49 mmHg (p = 0.00). CONCLUSIONS: The interventricular septum, posterior wall, and left ventricular mass decreased significantly after aortic valve replacement. The maximum and mean transvalvular gradient decreased significantly after surgery for aortic valve replacement.

Mutations Related to Antiretroviral Resistance Identified by Ultra-Deep Sequencing in HIV-1 Infected Children under Structured Interruptions of HAART.

Although Structured Treatment Interruptions (STI) are currently not considered an alternative strategy for antiretroviral treatment, their true benefits and limitations have not been fully established. Some studies suggest the possibility of improving the quality of life of patients with this strategy; however, the information that has been obtained corresponds mostly to studies conducted in adults, with a lack of knowledge about its impact on children. Furthermore, mutations associated with antiretroviral resistance could be selected due to sub-therapeutic levels of HAART at each interruption period. Genotyping methods to determine the resistance profiles of the infecting viruses have become increasingly important for the management of patients under STI, thus low-abundance antiretroviral drug-resistant mutations (DRM's) at levels under limit of detection of conventional genotyping (<20% of quasispecies) could increase the risk of virologic failure. In this work, we analyzed the protease and reverse transcriptase regions of the pol gene by ultra-deep sequencing in pediatric patients under STI with the aim of determining the presence of high- and low-abundance DRM's in the viral rebounds generated by the STI. High-abundance mutations in protease and high- and low-abundance mutations in reverse transcriptase were detected but no one of these are directly associated with resistance to antiretroviral drugs. The results could suggest that the evaluated STI program is virologically safe, but strict and carefully planned studies, with greater numbers of patients and interruption/restart cycles, are still needed to evaluate the selection of DRM's during STI.

[Factors associated with advanced thyroid cancer in pediatric patients in a high specialty medical unit in Northeast Mexico]. / Factores asociados a estadios avanzados de cáncer tiroideo en pacientes pediátricos de una UMAE del noreste de México.

INTRODUCTION: Thyroid cancer represents 2% of all childhood malignances. Its incidence rises 1.1% per year. In comparison with adults, childhood thyroid cancer is detected in a more advanced stage, but with a survival rate above 95%. The objective of this study was to evaluate whether there are factors associated with advanced stages of thyroid cancer in pediatric patients. RESULTS: Nineteen patients were included, 13 (68.4%) were female and six male, all between 7-15 years, with a median of 11 years. Fifteen in advanced and four in early stage. The median age of patients in advanced stage at time of diagnosis was 10.6 years (7-15) and 13.2 (12-14) were in early stage (p=0.075). There was a delay of nine months to get a diagnosis in advanced stage, and 7.2 in early stage (p=0.931). Three of the patients with advanced stage and two with early stage were from Nuevo León (Mexico) and the rest were foreign (p=0.567). In the group with advanced stage, two had thyroid cancer familiar history, and none in the early stage group (p=0.452). Nine patients in advanced stage and three in early stage presented thyroid nodule as the first sign of illness. Six patients in advanced stage and one in early stage presented goiter (p=0.590). None of the studied patients had radiation history. Six patients in advanced stage and one in early stage suffered from Hashimoto's Thyroiditis (p=0.590). Eleven in advanced stage and one in early stage had papillary histologic variety. Four in advanced stage and three in early stage had papillary histologic variety with a follicular patter (p=0.083). Eight patients presented lung metastasis at time of diagnosis (p=0.061). CONCLUSIONS: There are no factors associated with advanced stage thyroid cancer in pediatric populations. Although half of studied patients presented lung metastasis, treatment response and survival is satisfactory.

[Pulmonary complications in pediatric patients with primary immunodeficiency]. / Complicaciones pulmonares en pacientes pediátricos con inmunodeficiencias primarias.

INTRODUCTION: Primary immunodeficiencies comprise diseases that impair the immune system. Clinical manifestations are characterized by recurrent respiratory infections, which may be complicated by bronchiectasis, peribronchial thickening, abscesses, bullae, and pulmonary fibrosis. The aim of this study was to determine pulmonary complications in pediatric primary immunodeficiency by type. RESULTS. We included 65 patients, 28 patients with humoral immunodeficiency, four with cellular immunodeficiency, 13 with well-defined syndromes, and 20 with phagocytic defects. Patients with cellular immunodeficiency with symptoms began at an early age, and were diagnosed before one year of age (p = 0.01 ). Patients with humoral immunodeficiency had more frequent and early respiratory symptoms (p = 0.01 ). The most common respiratory diseases were acute suppurative otitis media, with sinusitis and pneumonia more common in humoral immunodeficiencies and phagocytic defects. The most common pulmonary complications were bronchiectasis and pulmonary fibrosis interstitial damage, with no statistical difference between primary immunodeficiency type. Pulmonary function tests showed greater impairment in patients with phagocyte defects, but no statistical difference (p = 0.28). The presence of pulmonary complications showed no difference when compared by type of immunodeficiency, agammaglobulinemia only (p = 0.02). CONCLUSIONS: Cell immunodeficiencies are diagnosed as early as the onset of symptoms before the patient is one year old. Humoral immunodeficiencies present maximum upper and lower respiratory infections and increased risk of pulmonary complications, especially agammaglobulinemia.

[Zoledronic acid (zoledronate) in children with osteogenesis imperfecta]. / Ácido zoledrónico (zolendronato) en niños con osteogénesis imperfecta.

INTRODUCTION: Zoledronic acid or zo/edronate is a potent bisphosphonate that recently has been used in children with osteoporosis and osteogenesis imperfecta (01), so it could be an option in the treatment of children with this terrible disease that virtually condemns them to a life of pain and prostration. The aim of this study was to evaluate the clinical and biochemical conditions of pediatric patients with 01 before and after treatment with zo /edronate. RESULTS: We included 14 patients, median age six years (6 months to 14 years), eight (57.1 %) males and six (42 .9%) females, weight 19 kg (5.8-45 kg). According to the type of 01, six (42.9%) were type I, six (42.9%) type Ill, and two (14.2%) type IV The functional score (Bleck) previous to treatment was 4 (1-9) and 6 (2-9) after treatment (p = 0.001). Pain intensity prior to zo/edronate was 2 (1-9) and 0 (0-2) after (p = 0.008). Previous fractures five (1-15) and post-treatment one (0-2) (p = 0.001 ). There were no significant differences in calcium, phosphorus, alkaline phosphatase, and parathyroid hormone. CONCLUSIONS: Zoledronic acid decreases the number of bone fractures and pain in children with osteogenesis imperfect and improves functional status. The most common side effects were fever and bone pain within five days after the infusion,which disappear paracetamol. No adverse long-term effects such as hypocalcemia or hypoparathyroidism were reported.

[Genetic mutations and the relationship with clinical phenotype in patients with mucopolysaccharidosis type I in northeast Mexico]. / Mutaciones genéticas y su relación con el fenotipo clínico en pacientes con mucopolisacaridosis de tipo I en el noreste de México.

INTRODUCTION: The mutations found in the IDUA gene depend on racial and genetic background. The aim of this paper is to determine the mutations of the IDUA gene in patients with MPS I in the Northeast of Mexico and the relationship with phenotype. RESULTS: Molecular studies were performed in seven patients from Nuevo Leon with MPS I. Five patients had Hurler-Scheie phenotype and two had Hurler phenotype. Four patients (57.1%) had the mutation p.W402X, and two patients (28.5%) had the mutation p.533R, which are both common mutations found in MPS I. Three patients had a novel mutation p.180Ser, so the relationship phenotype/genotype is unknown. Six patients (85.7%) were heterozygotes and one (14.2%) was homozygote. There was a good phenotype/genotype relationship in patients with previously described mutations and only in one patient the genotype had no correlation with the expected phenotype. CONCLUSIONS: The most common mutation in these patients was p.W402X. The mutation p.180Ser has not been listed as a pathogenic mutation or as polymorphism in the data base of the IDUA gene. There was a good phenotype/genotype relationship.

[Rituximab in pediatric patients with systemic lupus erythematosus]. / Evolución de los pacientes pediátricos con lupus eritematoso sistémico tratados con rituximab.

UNLABELLED: Systemic lupus erythematosus (SLE) is an autoimmune disease that is more severe in pediatric population than in adults. Biological therapy with anti-CD20 (rituximab) in children with SLE was begun to use only a few years ago, in patients that do not respond to conventional therapy. The aim of this study is to determine the clinical response in pediatric patients with SLE that received treatment with rituximab in a third level hospital. RESULTS: Eight pediatric patients with SLE treated with rituximab were included. Female gender predominated with six (75%). The age at diagnosis of SLE was a mean of 11.3 ± 1.03 years. The mean time between the onset of symptoms and diagnosis was 4.12 ± 1.01 months, and the application of rituximab was 20.7 ± 6.2 months after diagnosis. The most common diagnostic criteria were: malar erythema, hematologic disease, arthritis and kidney disease. Positive ANA title was found in 62.5% of the patients. The clinical activity index MEX-SLEDAI before rituximab was 11.63 ± 6.8 points. Four patients (50%) died, they had activity index before rituximab of 23 ± 1.7 and the survivors of 12.2 ± 3.2 (p = 0.002). After treatment with rituximab the patients that died had 17.6 ± 8.5 points and the survivors 8 ± 2.1 (p = 0.038). In laboratory findings, only C3 and C4 had a significant change after treatment (p = 0.048 and 0.032). CONCLUSIONS: Rituximab reduces lupus activity index and increases complement levels in children with LES that don't respond to conventional therapy.