Alteraciones citogenéticas en pacientes con diagnóstico de infertilidad en Lima, Perú / Cytogenetic abnormalities in patients with infertility diagnosis in Lima, Peru

INTRODUCCIÓN: La infertilidad es una enfermedad multicausal y el componente genético representa uno de sus principales eventos. Si bien la distribución de la infertilidad puede variar entre poblaciones, las parejas de los países con bajos y medianos ingresos pueden verse más afectadas por la infertilidad, con una proporción de alteraciones citogenéticas aún no esclarecidas. OBJETIVO: Evaluar la frecuencia de alteraciones citogenéticas y su correlación con el número de abortos en pacientes peruanas con diagnóstico de infertilidad. MÉTODO: Se realizó un estudio de corte transversal en 400 pacientes de 18 a 60 años, de ambos sexos, con diagnóstico de infertilidad. Se registraron las características clínicas disponibles durante el examen genético y el análisis citogenético convencional fue con bandeo GTG en muestras de sangre periférica. El análisis de correlación se realizó con la prueba de Spearman. RESULTADOS: Del total, 389 pacientes cumplieron los criterios de inclusión, y de estos, 169 (43,44%) tuvieron reportes de abortos (promedio: 2,25, rango: 1-7). Hallamos una correlación significativa ente el número de abortos y las alteraciones citogenéticas (p < 0,000). Reportamos 25/289 (6,43%) alteraciones cromosómicas, de las que 11/25 (44%) fueron heterocromatinas constitutivas y 6/25 (24%) fueron translocaciones reciprocas. Las alteraciones citogenéticas más frecuentes fueron 16qh+ y 9qh+ (ambas con un 16%), y afectaron a 17 (68%) varones. CONCLUSIONES: Existe una moderada frecuencia de alteraciones citogenéticas en pacientes peruanos con diagnóstico de infertilidad, y las alteraciones más frecuentes fueron heterocromatina constitutivas. Además, evidenciamos una correlación significativa ente el número de abortos y las alteraciones citogenéticas.

INTRODUCTION: Infertility is a multicausal disease and the genetic component represents one of its main events. Although the distribution of infertility may vary between populations, couples in low-and-middle-income countries may be more affected by infertility with a proportion of cytogenetic alterations still unclear. OBJECTIVE: To evaluate the frequency of cytogenetic alterations and their correlation with the number of abortions in Peruvian patients with a diagnosis of infertility. METHOD: A cross-sectional study was carried out in 400 patients between 18 and 60 years-old, of both genders with a diagnosis of infertility. The clinical characteristics available during the genetic examination were recorded and the conventional cytogenetic analysis was with GTG banding in peripheral blood samples. The correlation analysis was performed with the Spearman test. RESULTS: Of the total 389 patients who met the inclusion criteria, of these 169 (43.44%) patients had reports of abortions (mean: 2.25, range: 1-7). We found a significant correlation between the number of abortions and cytogenetic alterations (p < 0.000). We report 25/289 (6.43%) chromosomal alterations, where 11/25 (44%) were constitutive heterochromatin, and 6/25 (24%) were reciprocal translocations. The most frequent cytogenetic alterations were 16qh + and 9qh + (both 16%), and affected 17 (68%) men. CONCLUSIONS: There is a moderate frequency of cytogenetic alterations in Peruvian patients diagnosed with infertility, where the most frequent alterations were constitutive heterochromatin. Furthermore, we evidenced a significant correlation between the number of abortions and cytogenetic alterations.

A rare case of dicentric ring chromosome and derivative ring chromosome Chimera / 中华医学遗传学杂志

OBJECTIVE@#Utilize high-resolution chromosome analysis and microarray detection to determine the genetic etiology of infertility of a 32-year old female patient.@*METHODS@#The peripheral blood of the patient was cultured for high-resolution chromosome G and C banding karyotype analysis, and then 750K SNP-Array chip detection was performed.@*RESULTS@#Karyotype analysis results showed that the patient's karyotype was 45,XX,-13 [7]/46,XX,r(13) (p13q34) [185]/46,XX,dic r(13;13)(p13q34;p13q34) [14]/ 47,XX,+der(13;13;13;13) (p13q34;p13q34;p13q34; p13q34), dic r(13;13) [1]/ 46,XX [3]. The microarray results showed that the patient had a 3.3 Mb deletion in the 13q34 segment of chromosome 13, which may be related to infertility.@*CONCLUSION@#Infertility of the patient reported in this article may be related to the deletion of chromosome segment (13q34-qter).

The molecular control of meiotic double-strand break (DSB) formation and its significance in human infertility / 亚洲男科学杂志(英文版)

Meiosis is an essential step in gametogenesis which is the key process in sexually reproducing organisms as meiotic aberrations may result in infertility. In meiosis, programmed DNA double-strand break (DSB) formation is one of the fundamental processes that are essential for maintaining homolog interactions and correcting segregation of chromosomes. Although the number and distribution of meiotic DSBs are tightly regulated, still abnormalities in DSB formation are known to cause meiotic arrest and infertility. This review is a detailed account of molecular bases of meiotic DSB formation, its evolutionary conservation, and variations in different species. We further reviewed the mutations of DSB formation genes in association with human infertility and also proposed the future directions and strategies about the study of meiotic DSB formation.

Falência ovariana precoce em portadores da pré-mutação do gene FMR1: revisão da literatura / Premature ovarian failure in FMR1 premutation carriers: a literature review

A mutação do gene FMR1 é um fator genético importante para a determinação multifatorial da idade da menopausa. Portadoras da pré-mutação podem ter a vida reprodutiva encurtada e devem ser alertadas sobre o risco de transmissão da Síndrome do X Frágil para seus descendentes. O objetivo deste trabalho foi mostrar dados atualizados sobre as implicações genotípica e fenotípica da pré-mutação do gene FMR1 na reprodução humana.

The FMR1 mutation is an important genetic factor in the multifactor determination of menopause age. Premutation carriers can have reproductive life shortened and should be alerted about the risk of transmitting the Fragile X Syndrome to their descendents. The purpose of this paper was to show updated data about the genotypic and phenotypic implications of FMR1 premutation on human reproduction.

Biological aspects of crosses between Triatoma maculata (Erichson, 1848) and Triatoma pseudomaculata Corrêa & Espínola, 1964 (Hemiptera: Reduviidae)

Due to morphological similarities between Triatoma maculata and T. pseudomaculata, which comprise the "maculate complex", both had been regarded as the same species until 1964. Considering that the studies on triatomine hybridization permit hypotheses formulation concerning origin and divergence of species, enabling a quantitative analysis of taxonomic relationships between species, the present investigation was aimed at broadening further understanding related to the capacity of hybrid production by determining the degree of reproductive isolation between T. maculata and T. pseudomaculata. Our results have demonstrated that T. maculata and T. pseudomaculata showed no differences regarding reproduction patterns and they are able to cross, generating infertile hybrids.

Overview on the first human cytogenetic research in Sudan

The present study is the first human cytogenetic project in Sudan which was titled: Cytogenetic and FISH analyses in Sudanese patients with dysmorphic features, ambiguous genitalia, and infertility. The aim of the present study was not only to characterize the genetic alterations in patients with dysmorphic features, ambiguous genitalia and/or infertility among Sudanese population, but also to attract the medical community attention to the importance of human cytogenetics in clinical genetics practice, and also to facilitate the introduction and clinical application of such valuable service in Sudan. In this study chromosomal G-banding and fluorescence in situ hybridisation [FISH] analysis were performed on 44 Sudanese patients, 29 females, 14 males, and one patient with unassigned sex. Patients age ranging between 17 days-39 years [mean 18 years]. Of the 44 patients, 20 had ambiguous genitalia, 8 dysmorphic features, 11 have puberty and/or fertility complains, and 5 were healthy individual [parents of 3 patients with dysmorphic features]. Cytogenetic analysis of 20 patients complaining of ambiguous genitalia [13 females and 6 males, and one case with unassigned sex] showed that 8 has karyotypes different from their assigned sex and the other cases showed karyotypes consistent with Edward syndrome [47,XX,+18] [case 7], and a case with 45yXdel[X][pll] [case 11] respectively, when using FISH the 45,Xdel[X][pl 1] case showed translocation of the SRY [sex-determining region Y], gene to the active X chromosome. For the 8 patients of dysmorphic features; five showed karyotypes consistent with Down syndrome, of which one showed Robertsonian translocation, with both FISH and ordinary G-banding, and the other three showed normal karyotypes. All the parents showed normal karyotypes. Among the infertility cases all showed normal karyotypes, except for two which showed karyotypes consistent with Turner syndrome and one which showed a male karyotype although the case was raised as a female; ultrasound showed a mass in the position of prostate. The study, the ever first one in Sudan, assured the importance, the possibility, and the need for cytogenetic and FISH analysis in diagnosis, management and genetic counseling of genetic diseases caused by constitutional chromosomal changes among Sudanese patients

Estudio citogenético de 663 parejas con problemas reproductivos / Cytogenetic study of 663 partners with reproductive problems

Las alteraciones cromosómicas son invocadas invariablemente como una de las causas que es necesario estudiar en primera instancia, cuando se desea establecer el diagnóstico etiológico de una pareja con problemas reproductivos. En este trabajo presentamos los resultados de 1326 exámenes citogenéticos correspondientes a 663 parejas con este tipo de problemas en un período de 17 años, en el cual se obtuvo un rendimiento del 9.2 por ciento, similar a otros reportes de la literatura. Las alteraciones estructurales más frecuentes fueron las translocaciones recíprocas, seguidas de las translocaciones robertsonianas, las inversiones y los mosaicos estructurales

Perda reprodutiva associada a translocaçäo cromossômica tipo robertsoniana / Reproductive loss associated with chromossomic translocation type robertsonian

Os autores apresentam um caso de infertilidade de seis anos, com história de perda reprodutiva na 17ª semana de gestaçao, associada a translocaçao equilibrada tipo Robertsoniana 13/13 em um dos cônjuges.

Infertility and genetic factors

A literatura básica referente aos problemas de infertilidade foi revista, encontrando-se freqüentemente resultados conflitantes. Os fatores mais importantes säo o nível social e econômico, comunicaçäo de massa e os programas escolares. Os hábitos pessoais, tais como tabagismo e o uso de contraceptivo oral, também säo importantes na infertilidade. Em relaçäo as causas genéticas de infertilidade devem ser mencionadas (a) reduçäo dos níveis de hormônios ao redor da 10ª semana de gestaçäo, (c) alta incidência de anormalidade no espermograma, (d) alta incidência de abortos prévios. A gametogênese imperfeita e a evoluçäo retardada säo outros fatores genéticos. O papel causal das anomalias dos cromossomos no aborto recurrente é de pequena monta. As análises citogenéticas têm demonstrado nosaicismo, transdeslocamento, paridade anormal e outras alteraçöes numéricas na mulher infértil

Rendimiento del estudio cromosómico en 270 parejas con problemas reproductivos / Chromosomical study of 270 partners with infertility problems

El estudio citogenético en parejas con pérdida reproductiva a repetición sirve para detectar alteraciones estructurales cromosómicas que no producen un efecto fenotípico en los portadores, pero pueden explicar los abortos por la producción de gametos desbalanceados genéticamente. Presentamos la investigación realizada en 270 parejas que demostró una anomalía cromosómica en un 9,2%de ellas. Esto permite impartir un consejo genético respecto a la trascendencia del hallazgo, el riesgo de recurrencia y las alternativas reproductivas. En un 8,6%se encontró algunas líneas celulares con alteraciones de los cromosomas sexuales que no representarían un riesgo tan concreto

Análisis cromosómico del ganado criollo venezolano / Chromosomal analysis of Venezuelan creole cattle

A fin de mejorar la producción animal a travéz de la selección artificial, se realizó por primera vez en Venezuela el diagnóstico cromosómico de una muestra de 51 animales (9 machos y 6 hembras) provenientes de un rebaño Criollo Río Limón Venezolano, la cual es una raza de doble propósito bien adaptada al clima tropical. El rebaño en estudio presenta una baja tasa de fertilidad, es decir un reducido número de hembras preñadas después de finalizado el período de monta. Se cultivaron células de sangre periférica heparinizada, para obtener placas metafásica que fueron teñidas según las técnicas de bandeo G y C para la identificación de los cromosomas. Todos los toros tenían el cromosoma Y submetacéntrico característico de Bos taurus. La translocación 1/29 se encontró en 2 toros (22.2%de los machos analizados). El hallazgo de esta anomalía cromosómica, en esta pequeña muestra diagnosticada, asociada a problemas de fertilidad en el ganado Criollo demuestra la urgente necesidad de proseguir este tipo de estudios, para establecer la incidencia del problema en la población de ganado Criollo de Venezuela