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Mutations in Recombinase Activating Genes 1 and 2 (RAG1/2) results in human severe combined immunodeficiency (SCID). The products of these genes, are essential for V(D)J rearrangement of the antigen receptors during lymphocyte development. Nonsense mutations in RAG1 or RAG2 are associated with the most severe clinical and immunological phenotypes, whereas patients with missense mutations may develop leaky SCID or Omenn syndrome (OS). A group of non-previously recognized clinical phenotypes associated with granulomata and/or autoimmunity have been described as a consequence of hypomorphic mutations. Here we present six patients from unrelated families with missense variants in RAG1 or RAG2. Phenotypes observed in these patients ranged from OS to severe mycobacterial infections and granulomatous disease. Moreover, we report the first evidence of two previously unidentified variants as causative of pathological manifestations associated to immunodeficiency. This study represents the first case series of RAG1 or RAG2 deficient patients from Mexico and Latin America.

Objective To compare serum resistin concentrations between prepubertal girls with a BMI > 85th percentile and girls with precocious puberty (CPP) who have and have not undergone GnRH analog treatment. Patients and methods This is a cross-sectional study in girls with a BMI > 85th percentile and a median age of 8 years. We included 31 girls with CPP who did not receive treatment (CPPoT), 23 girls with CPP who were treated with leuprolide (CPPT), 22 prepubertal girls and 24 pubertal girls. Anthropometric data and the fasting plasma concentrations of lipids, glucose, insulin, and resistin were measured. Results The z-BMI scores were similar among the groups (p = 0.344), and body fat percentage (BF%) was similar among CPPT, CPPoT and prepubertal girls (p = 0.151). Resistin and insulin levels were lower in girls with CPP (CPPT and CPPoT) than in prepubertal and pubertal girls (median resistin level: CPPT 11.8 pg/ml vs CPPoT 11 pg/ml vs prepubertal 16 pg/ml vs pubertal 16 pg/ml, p = 0.001; median insulin level: CPPT 10.7 μUI/mL vs CPPoT 10.2 μUI/mL vs prepubertal 14.4 μUI/mL vs pubertal 32 μUI/mL p = 0.02). ANCOVA analysis, after adjustments for pubertal stage, BF% and z-BMI, showed that CPP modifies resistin levels (F = 31.4; p = 0.0001) independently of these parameters (p Conclusions In the group of girls with overweight or obesity, the resistin level was lower in girls with CPP than in prepubertal and pubertal girls. More studies are needed to understand the role of resistin in CPP patients.

To compare cardiometabolic factors and adipokines between patients with recently diagnosed CPP and controls without CPP, paired by BMI Z scores (BMIz) and classified into girls with adequate nutritional status and girls who are overweight or obese.This cross-sectional study was performed from January 2012 to May 2015 at two tertiary care pediatric centers in Mexico City. We included female patients with idiopathic CPP without other chronic pathology and healthy controls. Patients were divided into groups, BMI 85th and BMI ≥ 85th percentile, according to 2000 CDC Growth Charts. Anthropometric data and fasting plasma concentrations of lipids, glucose, insulin, and leptin were assessed.There were 73 patients with CPP and 82 without CPP. Sixty-six patients were matched between the groups; no significant difference was noted between the groups according to zBMI. However, differences in the bone/chronological age relationship, birth weight and proportions in different Tanner stages were observed. Among girls with normal BMI, the percentage of body fat (24.6% vs 18.9%, p 0.001), serum triglycerides (102.9 vs 54.3 mg/dl, p 0.001), leptin (7.46 vs 5.4 ng/ml, p = 0.010) and free leptin (0.44 vs 0.29 ng/ml, p = 0.044) were higher in those with CPP; additionally, girls with CPP presented a higher proportion of hypertriglyceridemia. In the overweight/obese group, adiponectin levels were lower in girls with CPP (6.23 vs 7.28 pg/ml, p = 0.011).Girls with CPP and normal BMI at diagnosis had a worse cardiometabolic profile, as reflected by higher levels of free leptin, and higher proportion of hypertriglyceridemia than girls without CPP.

Chronic granulomatous disease (CGD) is a primary immunodeficiency characterized by an inability of phagocytes to produce reactive oxygen species, impairing their killing of various bacteria and fungi. We summarize here the 93 cases of CGD diagnosed in Mexico from 2011 to 2019. Thirteen Mexican hospitals participated in this study. We describe the genetic, immunological, and clinical features of the 93 CGD patients from 78 unrelated kindreds. Eighty-two of the patients (88%) were male. All patients developed bacterial infections and 30% suffered from some kind of fungal infection. Fifty-four BCG-vaccinated patients (58%) presented infectious complications of BCG vaccine. Tuberculosis occurred in 29%. Granulomas were found in 56% of the patients. Autoimmune and inflammatory diseases were present in 15% of patients. A biological diagnosis of CGD was made in 89/93 patients, on the basis of NBT assay (n = 6), DHR (n = 27), and NBT plus DHR (n = 56). The deficiency was complete in all patients. The median age of biological diagnosis was 17 months (range, 0–186 months). A genetic diagnosis was made in 83/93 patients (when material was available), corresponding to CYBB (n = 64), NCF1 (n = 7), NCF2 (n = 7), and CYBA (n = 5) mutations. The clinical manifestations in these Mexican CGD patients were similar to those in patients elsewhere. This cohort is the largest in Latin America. Mycobacterial infections are an important cause of morbidity in Mexico, as in other countries in which tuberculosis is endemic and infants are vaccinated with BCG. X-linked CGD accounted for most of the cases in Mexico, as in other Latin American countries. However, a significant number of CYBA and NCF2 mutations were identified, expanding the spectrum of known causal mutations.

To evaluate the resistin/uric acid index as a prognostic factor associated with body mass index (BMI) z-score change after 1 year of lifestyle interventions for obesity.In this prospective cohort study, we included 102 adolescents with overweight or obesity (BMI ≥85th percentile). Weight and height were measured at the start of the lifestyle change intervention and 12 months later. Serum levels of resistin and uric acid were quantified at the beginning of the intervention. The intervention consisted of nutrition education, exercise, and physical activity promotion.The sample included 54 girls and 48 boys; the median age was 11 years (range 10-16 years). The BMI z-score decreased during follow-up (median BMI z-score at baseline was 1.81 vs 1.70 after 1 year, P.001). The resistin/uric acid index was positively correlated with BMI z-score change (r = 0.27, P.01). In the linear regression analysis, the resistin/uric acid index was significantly associated with BMI z-score modification at the 12-month follow-up (β = 0.17; 95% CI 0.08-0.26; P.01).The resistin/uric acid index can be considered a prognostic factor for identifying adolescents with overweight or obesity with a greater probability of improving their BMI. This index could help establish different interventions for adolescents with overweight and obesity; however, additional studies are needed to confirm the usefulness of this index.

International scientific experts in food, nutrition, dietetics, endocrinology, physical activity, paediatrics, nursing, toxicology and public health met in Lisbon on 2–4 July 2017 to develop a Consensus on the use of low- and no-calorie sweeteners (LNCS) as substitutes for sugars and other caloric sweeteners. LNCS are food additives that are broadly used as sugar substitutes to sweeten foods and beverages with the addition of fewer or no calories. They are also used in medicines, health-care products, such as toothpaste, and food supplements. The goal of this Consensus was to provide a useful, evidence-based, point of reference to assist in efforts to reduce free sugars consumption in line with current international public health recommendations. Participating experts in the Lisbon Consensus analysed and evaluated the evidence in relation to the role of LNCS in food safety, their regulation and the nutritional and dietary aspects of their use in foods and beverages. The conclusions of this Consensus were: (1) LNCS are some of the most extensively evaluated dietary constituents, and their safety has been reviewed and confirmed by regulatory bodies globally including the World Health Organisation, the US Food and Drug Administration and the European Food Safety Authority; (2) Consumer education, which is based on the most robust scientific evidence and regulatory processes, on the use of products containing LNCS should be strengthened in a comprehensive and objective way; (3) The use of LNCS in weight reduction programmes that involve replacing caloric sweeteners with LNCS in the context of structured diet plans may favour sustainable weight reduction. Furthermore, their use in diabetes management programmes may contribute to a better glycaemic control in patients, albeit with modest results. LNCS also provide dental health benefits when used in place of free sugars; (4) It is proposed that foods and beverages with LNCS could be included in dietary guidelines as alternative options to products sweetened with free sugars; (5) Continued education of health professionals is required, since they are a key source of information on issues related to food and health for both the general population and patients. With this in mind, the publication of position statements and consensus documents in the academic literature are extremely desirable., This Consensus is the results of the Ibero–American Consensus Meeting on Low- and No-Calorie Sweeteners held in Lisbon, Portugal, 2–4 July 2017, that was supported with funding from the Nutrition Research Foundation (FIN). The different organizations and institutions that participated and supported this Consensus are greatly acknowledged.

Objective To evaluate the results of a lysosomal newborn screening (NBS) program in a cohort of 20,018 Mexican patients over the course of 3 years in a closed Mexican Health System (Petroleos Mexicanos [PEMEX] Health Services). Study design Using dried blood spots (DBS), we performed a multiplex tandem mass spectrometry enzymatic assay for six lysosomal storage disorders (LSDs) including Pompe disease, Fabry disease, Gaucher disease, mucopolysaccharidosis type I (MPS-I), Niemann–Pick type A/B, and Krabbe disease. Screen-positive cases were confirmed using leukocyte enzymatic activity and DNA molecular analysis. Results From July 2012 to April 2016, 20,018 patients were screened; 20 patients were confirmed to have an LSD phenotype (99.9 in 100,000 newborns). Final distributions include 11 Pompe disease, five Fabry disease, two MPS-I, and two Niemann–Pick type A/B patients. We did not find any Gaucher or Krabbe patients. A final frequency of 1 in 1001 LSD newborn phenotypes was established. Discussion NBS is a major public health achievement that has decreased the morbidity and mortality of inborn errors of metabolism. The introduction of NBS for LSD presents new challenges. This is the first multiplex Latin–American study of six LSDs detected through NBS.

Resumen Introduccion Las enfermedades prevenibles con vacunacion, como la varicela, merecen el analisis de la situacion vacunal como parte de una politica de salud. Este inmunogeno no forma parte del esquema mexicano de vacunacion, y en la mayoria de los casos solamente se aplica en el sector privado. El presente estudio se realizo con el objetivo de analizar la experiencia y los resultados del programa institucional de inmunizacion contra varicela. Metodos Se analizo el periodo de 2002–2009. Se consultaron las bases de datos correspondientes a casos de varicela diagnosticados en el Hospital Central Sur de Alta Especialidad y se obtuvieron las frecuencias de casos de varicela diagnosticadas en consulta externa pediatrica en ninos menores de 15 anos de edad. Se calcularon frecuencias simples e incidencias acumuladas de casos por cada 100 menores. Resultados Se identifico a un total de 671 pacientes con varicela, y correspondio una tasa de morbilidad por enfermedad exantematica por varicela de 0,48 casos/10.000 pacientes pediatricos menores de 15 anos durante el periodo de 1999–2001. Durante los anos 2008 y 2009 se observo una disminucion en la tendencia de la incidencia de los casos con tasas de 0,65 a 0,49 casos, respectivamente. Conclusiones Si bien es cierto que los porcentajes de cobertura han sido variables a traves del tiempo, no es hasta el ano 2009 cuando se logra una cifra aceptable del 80%.