Antenatal Diagnosis of De Novo Balanced Structural Chromosome Aberrations in Latin America.

INTRODUCTION The consequences of de novo balanced structural chromosome aberrations diagnosed antenatally are unpredictable, and, as a result, they introduce uncertainty into genetic counseling decisions. OBJECTIVE Describe de novo balanced structural aberrations present at antenatal diagnosis in samples from pregnant women in five Latin American countries and determine their effect on carrier individuals. METHODS This was a retrospective observational study based on analysis of 109,011 antenatal tests conducted from January 1981 to December 2016 in Cuba, Uruguay, Costa Rica, Mexico, and Colombia. Thirteen cytogenetic laboratories provided information that included the cases analyzed during the study period; number of de novo balanced structural aberrations diagnosed antenatally; number of diagnoses with de novo balanced structural aberrations that resulted in termination of pregnancy; detailed descriptions of the karyotypes of de novo balanced structural aberration carriers, and descriptions of the form of diagnosis, including types of samples used (amniotic fluid, chorionic villus or fetal blood). Each laboratory also provided pathology reports and genetic counseling at time of diagnosis. Postnatal followup for pregnancies carried to term continued for at least two years. RESULTS Of the 109,011 antenatal tests studied, 72 (0.07%) showed de novo balanced structural aberrations. These events primarily involved chromosomes 1, 2, 7, 14, 18, and 20. Of the 79 breakpoints identified, the most common were 5p15.3, 7q11.2, 7q22, and 14q24. We identified three breakpoints corresponding to 3.8% (3q13.1, 3q13.2, and 9p12) that were not reported in other studies of de novo balanced structural aberrations diagnosed antenatally in patients from other geographic regions or in studies of chromosomal fragile sites. Two of these breakpoints (3q13.1 and 3q13.2) were associated with high risk of phenotypic abnormalities. Information on antenatal or postnatal followup was available for 62 (86%) of de novo balanced structural aberration carriers; of the 44 carriers with postnatal followup, 10 had phenotypic abnormalities. CONCLUSIONS Three new de novo breakpoints were identified, presumably related to genetic admixture characteristics in Latin America. Since some diseases associated with de novo balanced structural aberrations detected antenatally have a late onset, followup for at least two years is recommended for carriers of these aberrations. The information in this study is useful in genetic counseling for pregnant women in Latin America.

Síndrome de Meckel - Gruber recurrente / Recurrent Meckel - Gruber syndrome

Se describe el caso clínico de una adolescente de 18 años de edad, con 20,1 semanas de gestación, quien fue remitida por primera vez en 2009 al Centro Provincial de Genética, fecha en la que ya estaba casada con su pareja actual. A partir de ahí se sucedieron una serie de eventos obstétricos desfavorables y, finalmente, teniendo en cuenta los hallazgos ecográficos y la recurrencia de estos en la misma paciente se comprobó que ella y su esposo eran portadores de la mutación que produce el síndrome de Meckel - Gruber(AU)

The case report of an 18 years adolescent with 20.1 weeks of gravidity is described who was referred for the first time in 2009 to the Genetics Provincial Center, when she was already married with her current couple. Since that time on, a series of unfavorable obstetric events appeared and, finally, taking into account the echographic findings and its recurrence in the same patient, it was proven that she and her husband were carriers of the mutation that produces the Meckel - Gruber syndrome.(AU)

Un niño extraordinario fallecido a causa del síndrome de Hurler-Scheie / An extraordinary deceased child due to the Hurler-Scheie syndrome

Se expone la experiencia personal de una madre que debió enfrentar el síndrome de Hurler-Scheie, rara enfermedad padecida por su hijo ya fallecido, con vistas a demostrar que la observación de los cambios producidos en un niño, es vital para su desarrollo. El cuidado hacia un menor con esta afección resulta indispensable para lograr una infancia con calidad de vida; por tanto, el sistema de salud cubano debe continuar diseñando estrategias que garanticen un diagnóstico precoz y la posibilidad de alternativas terapéuticas oportunas como la terapia de reemplazo enzimático(AU)

The personal experience of a mother that faced the Hurler-Scheie syndrome, strange disease suffered from his son already deceased, is exposed with the purpose to demonstrate that the observation of the changes occurring in a child, is vital for his development. The care toward a young child with this disorder is indispensable to achieve a childhood with life quality; therefore, the Cuban health system should continue designing strategies that guarantee an early diagnosis and the possibility of opportune therapeutic alternatives as the enzymatic substitution therapy(AU)

Interacción genoma-ambiente en la aparición de la diabetes mellitus de tipo 2 / Genome-environment Interaction in the ocurrence of type 2 diabetes mellitus

Se efectuó un estudio analítico y observacional de casos y controles en el área de salud perteneciente al Policlínico "Josué País García" de Santiago de Cuba, durante el trimestre de septiembre a noviembre del 2010, con vistas a determinar la interacción genoma-ambiente en la aparición de la diabetes mellitus de tipo 2. El grupo de estudio contempló a 80 integrantes con dicha enfermedad, seleccionados mediante muestreo aleatorio simple; y el tomado como control, 160 personas sin ella. Se aplicó la prueba de Ji al cuadrado, con un nivel de significación de 0,05, y se calculó la oportunidad relativa para evaluar la magnitud de asociación entre las variables. Los factores de riesgo más significativos resultaron ser la obesidad y el sedentarismo, así como la existencia de la afección en familiares de primer grado en los integrantes del grupo de casos. Asimismo, se evidenció la interacción de un genoma predisponente con los factores ambientales adversos, por lo que se recomienda trabajar en la atención primaria de salud sobre la base de los agentes de riesgo conocidos, que pueden influir en la inicio de esta entidad clínica.

An analytic and observational study of cases and controls was carried out in the health area belonging to "Josué País García" Polyclinic in Santiago de Cuba, during the trimester from September to November, 2010, with the purpose of determining the interaction genome-environment in the ocurrence of type 2 diabetes mellitus. The study group was constituted by 80 patients with this disease, selected by means of simple random sampling; and the control group included 160 people without it. The X² test, with 0,05 significance level was applied, and the odds ratio was calculated to evaluate the association magnitude between the variables. The most significant risk factors were obesity and sedentary lifestyle, as well as the existence of the disorder in first degree relatives from patients of the case group. Likewise, the interaction of a predisposing genome with the adverse environmental factors was evidenced, for what it is recommended to work in the primary health care on the base of the well-known risk agents which may influence in the beginning of this clinical entity.

Interacción genoma-ambiente en la aparición de la diabetes mellitus de tipo 2 / Genome-environment Interaction in the ocurrence of type 2 diabetes mellitus

Se efectuó un estudio analítico y observacional de casos y controles en el área de salud perteneciente al Policlínico Josué País García de Santiago de Cuba, durante el trimestre de septiembre a noviembre del 2010, con vistas a determinar la interacción genoma-ambiente en la aparición de la diabetes mellitus de tipo 2. El grupo de estudio contempló a 80 integrantes con dicha enfermedad, seleccionados mediante muestreo aleatorio simple; y el tomado como control, 160 personas sin ella. Se aplicó la prueba de Ji al cuadrado, con un nivel de significación de 0,05, y se calculó la oportunidad relativa para evaluar la magnitud de asociación entre las variables. Los factores de riesgo más significativos resultaron ser la obesidad y el sedentarismo, así como la existencia de la afección en familiares de primer grado en los integrantes del grupo de casos. Asimismo, se evidenció la interacción de un genoma predisponente con los factores ambientales adversos, por lo que se recomienda trabajar en la atención primaria de salud sobre la base de los agentes de riesgo conocidos, que pueden influir en la inicio de esta entidad clínica(AU)

An analytic and observational study of cases and controls was carried out in the health area belonging to Josué País García Polyclinic in Santiago de Cuba, during the trimester from September to November, 2010, with the purpose of determining the interaction genome-environment in the ocurrence of type 2 diabetes mellitus. The study group was constituted by 80 patients with this disease, selected by means of simple random sampling; and the control group included 160 people without it. The X2 test, with 0,05 significance level was applied, and the odds ratio was calculated to evaluate the association magnitude between the variables. The most significant risk factors were obesity and sedentary lifestyle, as well as the existence of the disorder in first degree relatives from patients of the case group. Likewise, the interaction of a predisposing genome with the adverse environmental factors was evidenced, for what it is recommended to work in the primary health care on the base of the well-known risk agents which may influence in the beginning of this clinical entity(AU)