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.

Keywords: CCRs; Chromothripsis; Complex translocations; Reproduction.

Fig. 1

a–e Embryos that have been selected and transferred in three consecutive cycles of ICSI procedures

Fig. 2

Patient’s Pedigree, showing the carriers of the complex chromosome translocation in the family (dark symbols) and miscarriages (small dark circles); offsprings with unknown gender

Fig. 3

Patient’s karyotype—46,XX,t(1;8;11)(p31;q13;q23) (8qter→8q13::1p31→1qter;8pter→8q13::11q23→11qter;11pter→11q23::1p31→1pter)

Fig. 4

Patient’s brother karyotype (a) and patient’s mother karyotype (b), both presenting the same chromosome rearrangement