A family study of complex chromosome rearrangement involving chromosomes 1, 8, and 11 and its reproductive consequences

Abstract

Complex chromosome translocations are structural chromosomal rearrangements involving three or more chromosomes and more than two breakpoints. A complex chromosome rearrangement was detected in a phenotypically normal female patient that was referred to the hospital for genetic counseling due to reproductive failure. A cytogenetic evaluation was performed, according to standard method of chromosomal analysis, using G-banding technique. The patient's karyotype showed a balanced complex chromosome rearrangement (BCCR) involving chromosomes 1, 8, and 11 with three breakpoints 1p31, 8q13, and 11q23. The karyotype designed according to ISCN (2013), is 46,XX,t(1;8;11)(p31;q13;q23) (8qter→8q13::1p31→1qter;8pter→8q13::11q23→11qter;11pter→11q23::1p31→1pter). Additionally, the proband's mother and brother were tested, resulting in the same exact translocation. In this study, we describe all possible meiotic segregations regarding this translocation, as well as the clinical phenotypes which could arise, if unbalanced products of conception survive. This is a rare case of familial complex chromosome rearrangement, giving a view for its reproductive consequences.

Familial Infertility (Azoospermia and Cryptozoospermia) in Two Brothers—Carriers of t(1;7) Complex Chromosomal Rearrangement (CCR): Molecular Cytogenetic Analysis

“…Such high values arise from the complexity of the rearrangement: i.e., simple type I CCR with three chromosomes involved, each with one breakpoint, generates 64 various unbalanced genotypes in spermatozoa, while in simple RCTs, a quadrivalent formation generates 16 different types of meiotic segregants. This fact clearly indicates an increased risk of reproductive failures in CCR carriers, mostly leading to miscarriages ( Supplementary Table S1) [15,29].…”

“…Structurally balanced or unbalanced aberrations involving more than two breakpoints on two or more chromosomes, known as complex chromosomal rearrangements (CCRs), have been described in over 250 papers [13][14][15]. Approximately 75% of CCRs appear de novo or are inherited maternally (70% of all familial cases) [16,17].…”

Preimplantation genetic testing for balanced complex chromosomal rearrangement carriers by comprehensive chromosome screening

“…According to the chromosome structure and complexity, CCRs are usually classified into three types [3][4][5] : three-way rearrangement, double two-way translocations, and exceptional CCRs. The first two involve translocations only, whereas exceptional CCRS often includes other structural distortions, such as translocation, inversion, insertion, and others.…”

A novel male 2;4;14 complex chromosomal translocation with normal semen parameters but 100% embryonic aneuploidy

“…Most CCTs associated with infertility report multiple first trimester losses. One report of a female patient with infertility was found to have CCT involving chromosomes 1, 8, and 11 in a manner identical to her mother and biological brother [1]. Another case report presents a known parental balanced complex chromosome translocation which resulted in a de novo, simple balanced translocation in the fetus [2].…”