RESUMO
Los portadores de anomalías estructurales cromosómicas equilibradas, a pesar de ser fe-notípicamente normales, tienen una competencia reproductiva disminuida de manera significativa conrespecto a la población general. Esto se debe a que, durante la gametogénesis, dependiendo de cómo sesegregue la alteración cromosómica en la meiosis I, se generarán gametos normales, equilibrados o des-equilibrados en mayor proporción que en portadores de cariotipos normales. Esta es la causa principalEstudio del efecto intercromosómico en portadores de anomalías cromosómicasestructurales equilibradas mediante PGT-SRStudy of the interchromosomal effect in carriers of balanced structuralchromosomal rearrangements by PGT-SR de la mayor tasa de abortos y descendencia con alteraciones que presentan los individuos portadores de inversiones ytranslocaciones recíprocas o robertsonianas. Otra posible fuente de gametos y/o embriones aneuploides, es el denominadoefecto intercromosómico (EIC), que consiste en una interferencia producida por una alteración cromosómica estructuralsobre la adecuada disyunción y segregación de otros cromosomas no involucrados en dicha alteración.Material y Métodos:Un total de 40 parejas fueron incluidas en el estudio, de las cuales 31 pertenecieron al grupo de es-tudio: catorce translocaciones robertsonianas, trece translocaciones recíprocas y cuatro de inversiones pericéntricas. Endiecinueve casos la mujer era portadora y en los doce restantes era el hombre el afecto. Nueve parejas con cariotipo normal,portadoras de una mutación responsable de enfermedad monogénica fueron incluidas en el grupo control. (AU)
Introduction: Carriers of balanced structural rearrangements, despite being phenotypically normal, they have a signifi-cantly decreased reproductive competence compared to the general population. The reason is because, during gametoge-nesis, depending on how the chromosomal alteration is segregated in meiosis I, normal, balanced, or unbalanced gameteswill be generated in greater proportion than in carriers of normal karyotypes. This is the main cause of the higher rate ofabortions and offspring with alterations that carriers of inversions, reciprocal translocations or Robertsonian translocationspresent. Another possible source of aneuploid gametes and/or embryos is the so-called interchromosomal effect (ICE),which consists of an interference produced by a structural chromosomal alteration on the proper disjunction and segregationof other chromosomes not involved in the rearrangement.Material and methods:A total of 40 couples were included in the study, of which 31 belonged to the study group: fourteenRobertsonian translocations, thirteen reciprocal translocations and four pericentric inversions. As for the affected parent,in nineteen of the cases the woman was the carrier of the chromosomal alteration and in the remaining twelve it was theman who was affected. Nine couples with a normal karyotype, carriers of a mutation responsible for monogenic disease,were included in the control group. (AU)
Assuntos
Humanos , Fertilização in vitro , Cromossomos , Células Germinativas , DiagnósticoRESUMO
IMMT gene codes for mitofilin, a mitochondrial inner membrane protein that regulates the morphology of mitochondrial cristae. The phenotype associated with mutations in this gene has not been yet established, but functional studies carried out show that its loss causes a mitochondrial alteration, both in the morphology of the mitochondrial crests and in their function. We present two cousins from an extended highly consanguineous family with developmental encephalopathy, hypotonia, nystagmus due to optic neuropathy. The likely pathogenic homozygous c.895A>G (p.Lys299Glu) variant in the IMMT gene co-segregates with the disease and associates altered mitochondrial cristae observed by electron microscopy.
