Hallazgos incidentales en medicina genómica / Incidental Findings in Genomic Medicine

Las técnicas de Biología Molecular de última generación, como es la secuenciación masiva en paralelo o NGS (Next Generation Sequencing), permite obtener gran cantidad de información genómica, la cual muchas veces va más allá de la detección de una variante patogénica en un gen que explique la patología (hallazgo primario). Es así como surgió desde hace años la discusión internacional respecto a la decisión a tomar frente a los hallazgos secundarios accionables, es decir, aquellos hallazgos de variantes clasificadas como patogénicas o probablemente patogénicas que no están relacionadas con el fenotipo del paciente, pero que tiene alguna medida preventiva o tratamiento posible y, por lo tanto, podría ser de utilidad para la salud del paciente. Luego de revisar la bibliografía internacional y debatir entre los expertos del Hospital de Pediatría Garrahan, se logró establecer una política institucional y reforzar el hecho de que se trata de una disciplina multidisciplinaria. Así, fue posible definir que solo se atenderá las cuestiones relacionadas con la edad pediátrica, dejando para un tratamiento posterior aquellas variantes detectadas en genes que sean accionables en edad adulta. En el Hospital Garrahan, ha sido posible definir claramente cómo proceder frente a los hallazgos secundarios, al adaptar el consentimiento informado a esta necesidad, definiendo cuándo serán informados, y sabiendo que serán buscados intencionalmente en los genes clínicamente accionables enlistados en la última publicación del American College of Medical Genetics and Genomics, siempre y cuando el paciente/padre/tutor lo consienta (AU)

The latest generation of molecular biology techniques, including massive parallel sequencing or NGS (Next Generation Sequencing), allows us to obtain a whealth of genomic information, which often goes beyond the detection of a pathogenic variant in a gene that explains the pathology (primary finding). As a result, an international discussion has arisen over the years regarding the decision-making concerning actionable secondary findings, it means, those findings of variants classified as pathogenic or probably pathogenic that are not related to the patient's phenotype, but which have some possible preventive measure or treatment and, therefore, could be useful for the patient's health. After reviewing the international literature and discussing among the experts of the Hospital de Pediatría Garrahan, an institutional policy was established and the concept that this is a multidisciplinary discipline was reinforced. Consequently, it has been defined that only issues related to children will be addressed, reserving those variants detected in genes that are actionable in adulthood for later treatment. At Garrahan Hospital, we were able to clearly define how to proceed with secondary findings by adapting the informed consent to this need, defining when they will be reported, and knowing that they will be intentionally searched for in the clinically actionable genes listed in the latest publication of the American College of Medical Genetics and Genomics, as long as the patient/parent/guardian consents (AU)

Comparative application of direct sequencing, PCR-RFLP, and cytogenetic markers in the genetic characterization of Pimelodus (Siluriformes: Pimelodidae) species: possible implications for fish conservation.

Pimelodus (Pimelodidae) is a genus comprising a group of South American species with complex taxonomic relationships. Cytogenetics, polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP), and sequencing data of mitochondrial genes were analyzed to characterize 4 Pimelodus species: P. fur, P. heraldoi, P. maculatus, and Pimelodus sp. All populations presented 2n=56 chromosomes and distinct karyotypic formulae. The heterochromatin distribution pattern and the number and location of 5S and 18S rDNA sites are discussed. The application of PCR-RFLP markers and sequencing of mitochondrial DNA genes provided species-specific haplotypes, which allowed us to differentiate the species studied. The mitochondrial gene sequences presented nucleotide mutations in the restriction sites and throughout the sequences, and they were mostly related to synonymous substitutions in the coded proteins; however, they did not affect the protein and its function. Comparing the data obtained using these 3 methodologies, the existence of a species complex in P. maculatus along the basins studied might be inferred, showing that cytogenetics is an important tool in studies focusing on the conservation or management of both natural and captive populations of these fishes.

Crecimiento en niños con Síndrome de Sotos / Growth in children with Sotos syndrome

El síndrome de Sotos se caracteriza por macrosomía, retraso del desarrollo, rasgos faciales típicos y alteraciones cerebrales. En el año 2002 se identificó al gen responsable de ésta patología NSD1, localizado en el brazo largo del cromosoma 5 (5q35.2-q35.3). El objetivo del trabajo fue describir las curvas de crecimiento de 6 niños con diagnóstico clínico de síndrome de Sotos seguidos en los Servicios de Crecimiento y Desarrollo y Genética del Hospital de Pediatría J. P. Garrahan. Material y Métodos: Se realizó un estudio de serie de casos, retrospectivo, observacional, descriptivo por revisión de historias clínicas, de los datos antropométricos (peso, estatura, perímetro cefálico, longitud tronco, estatura de ambos padres) edad ósea, desarrollo puberal y características clínicas. Se analizaron las curvas de distancia. Se calculó la diferencia de puntaje z de estatura y perímetro cefálico al nacer, 2, 6 años y al final del seguimiento. Resultados: la mediana de peso y longitud corporal al nacer fue estadísticamente mayor que la población argentina (p<0,05). Durante el primer y segundo año de vida se observó aceleración del crecimiento, siendo más evidente en estatura y perímetro cefálico que en peso. Luego de esa edad todos los niños mostraron macrocefalia y el 83% (5/6) alta estatura para la población con crecimiento normal. La mediana de puntaje z de IMC fue 0,61 (r: 0,12/1,80). Todos los niños mostraron tendencia a miembros largos. 67% presentó edad ósea avanzada. Uno de cinco niños mostró inicio puberal temprano: 9,21 años de edad. Conclusiones: La curva de crecimiento de estos seis niños con diagnostico de síndrome de Sotos muestran un patrón similar. La macrocefalia y alta estatura, presentes a partir de los dos años de edad, fue la principal característica de estos niños. El IMC fue normal en todos los niños

Crecimiento en niños con síndrome de Sotos / Growth in children with Sotos syndrome

El síndrome de Sotos se caracteriza por macrosomía, retraso del desarrollo, rasgos faciales típicos y alteraciones cerebrales. En el año 2002 se identificó al gen responsable de ésta patología NSD1, localizado en el brazo largo del cromosoma 5 (5q35.2-q35.3). El objetivo del trabajo fue describir las curvas de crecimiento de 6 niños con diagnóstico clínico de síndrome de Sotos seguidos en los Servicios de Crecimiento y Desarrollo y Genética del Hospital de Pediatría J. P. Garrahan. Material y Métodos: Se realizó un estudio de serie de casos, retrospectivo, observacional, descriptivo por revisión de historias clínicas, de los datos antropométricos (peso, estatura, perímetro cefálico, longitud tronco, estatura de ambos padres) edad ósea, desarrollo puberal y características clínicas. Se analizaron las curvas de distancia. Se calculó la diferencia de puntaje z de estatura y perímetro cefálico al nacer, 2, 6 años y al final del seguimiento. Resultados: la mediana de peso y longitud corporal al nacer fue estadísticamente mayor que la población argentina (p<0,05). Durante el primer y segundo año de vida se observó aceleración del crecimiento, siendo más evidente en estatura y perímetro cefálico que en peso. Luego de esa edad todos los niños mostraron macrocefalia y el 83% (5/6) alta estatura para la población con crecimiento normal. La mediana de puntaje z de IMC fue 0,61 (r: 0,12/1,80). Todos los niños mostraron tendencia a miembros largos. 67% presentó edad ósea avanzada. Uno de cinco niños mostró inicio puberal temprano: 9,21 años de edad. Conclusiones: La curva de crecimiento de estos seis niños con diagnostico de síndrome de Sotos muestran un patrón similar. La macrocefalia y alta estatura, presentes a partir de los dos años de edad, fue la principal característica de estos niños. El IMC fue normal en todos los niños.

Naturally occurring and melengestrol acetate-associated reproductive tract lesions in zoo canids.

As husbandry practices have improved, safe and effective contraception for captive wildlife management has become a necessity. Melengestrol acetate (MGA), a synthetic progestin, is highly effective and has been used in many zoo species. Long-term use of MGA has been associated with uterine lesions in zoo felids, but effects in zoo canids have not been evaluated. This retrospective study documented spontaneously occurring lesions and investigated the impact of MGA on the reproductive health of zoo canids. Reproductive tracts from adult females were submitted by US zoos to the Association of Zoos & Aquariums' Wildlife Contraception Center Health Surveillance Program. Reproductive tracts were sampled and processed for histopathologic examination following standard protocols. Microscopic evaluations were performed without prior knowledge of MGA treatment status. Prevalence of uterine lesions was evaluated and compared between MGA-treated animals (n = 20) and control (untreated) animals (n = 61). Common lesions within the study population as a whole included endometrial hyperplasia (predominantly cystic) (53%), hydrometra (33%), and adenomyosis (25%). Treatment with MGA was a risk factor for endometrial hyperplasia, hydrometra, fibrosis, and adenomyosis. Uterine mineralization occurred exclusively in MGA-treated animals. Results indicate that MGA contraception can lead to lesions that may permanently impair the fertility of females. Therefore, if long-term contraception of zoo canids is necessary, the use of alternate methods of reproductive control such as gonadotropin-releasing hormone (GnRH) analogs or GnRH vaccines that reduce gonadal hormone exposure should be pursued.

Dermatophilosis of Alpine Chamois (Rupicapra rupicapra) in Italy.

A proliferative dermatitis similar to the condition generally referred to as strawberry footrot was observed in two Alpine chamois (Rupicapra rupicapra) from Eastern Alps, Italy. Branching septated filaments and packets of PAS-positive coccoid organisms were observed in histological sections of the affected skin. The actinomycete, Dermatophilus congolensis, was isolated from crusted lesions in one chamois. As wild ruminants are presumed to be a reservoir of infection in the Alpine area, the authors discuss the potential role of chamois in the epidemiology of dermatophilosis.

Use of naloxone to reverse carfentanil citrate-induced hypoxemia and cardiopulmonary depression in Rocky Mountain wapiti (Cervus elaphus nelsoni).

With the use of a crossover study design, we investigated the respiratory and cardiovascular effects of naloxone administration in eight healthy Rocky Mountain wapiti (Cervus elaphus nelsoni) anesthetized with carfentanil (10 microg/kg i.m.) and xylazine (0.1 mg/kg). Anesthetized animals showed profound hypoxemia with mild hypercapnia, tachycardia, hypertension, and acidosis prior to naloxone administration. After monitoring equipment was placed, animals were administered either naloxone (2 microg/microg carfentanil i.v.) or an equivalent volume of normal saline. Mean values for PaO2, PaCO2, heart rate, and respiratory rate were significantly different between naloxone- and saline-treated groups, but mean blood pressure, hematocrit, and serum electrolyte concentrations were not. Mean PaO2 was 23.0 +/- 4.1 mm Hg prior to administration of naloxone or saline and increased to 50.2 +/- 7.3 mm Hg after naloxone administration. Mean PaO2 of saline-treated animals did not change significantly. Electrocardiograms of three saline-treated animals suggested myocardial hypoxia. Hypoxemia appeared to be caused by respiratory depression, hemodynamic alterations, and lateral recumbency. All but one animal remained anesthetized after naloxone administration. Anesthesia in all animals was reversed in < or = 4 min with naltrexone (100 mg/mg carfentanil i.v. s.c.) and yohimbine (0.1 mg/kg i.v.). One bolus of naloxone improved oxygenation in carfentanil-xylazine-anesthetized wapiti.

Isolation and characterization of Aujeszky's disease virus in captive brown bears from Italy.

An epizootic of Aujeszky's disease (pseudorabies) in four captive European brown bears (Ursus arctos) in November 1994, in the Val di Non, Trentino Region, Italy, was linked to consumption of raw pork. Affected animals had severe pruritus resulting in self-mutilation, and all four died within 24 hr after onset of clinical signs. Aujeszky's disease virus was isolated on first passage from the brain and was characterized by means of restriction endonuclease analysis. Based on these data, we believe that bears are extremely susceptible to the disease, and that wildlife managers should consider pseudorabies as a potential risk for the captive and wild bear populations.

Hospital malnutrition: incidence and prospective evaluation of general medical patients during hospitalization.

The incidence of malnutrition and the effect of hospitalization was evaluated in 100 consecutive admissions to the Clinical Pathology R Department of the University of Genoa. Nutritional deficiencies were evaluated at the time of admission and discharge from the Hospital, among patients hospitalized 2 weeks or longer, using the following nutrition-related parameters: body fat, muscle proteins, weigh, rate of weight loss plasma proteins level, vitamin B12 and folic acid plasma level, plasma iron and ferritin. We also considered the nutritional alterations in malnourished patients with relation to appetite decrease and to pathological status. At the admission to the hospital, the findings showed a high incidence (79%) of alterations in some nutritional parameters. In patients with nutritional impairments we observed a worsening of most of the nutritional parameters during hospitalization, especially in patients with severe appetite decrease and those affected by sepsis, neoplastic, gastric and renal diseases.