Tetraploidy in a 26‐month‐old girl (cytogenetic and molecular studies)

Abstract

Liveborn infants with tetraploidy are very rare in human pregnancies and usually die during the first days or months. Seven cases of liveborn infants with tetraploidy have previously been reported. Among them only two 92, XXXX infants survived for longer than 12 months. Here we report on the case of a 26-month-old girl with tetraploidy. The main clinical features of tetraploidy are facial dysmorphism, severely delayed growth and developmental delay. On the basis of molecular studies we discuss the possible origin of the additional chromosome sets in our proband. To our knowledge, this infant is the first reported case of tetraploidy who lived up to 26 months.

Parental origin of the two additional haploid sets of chromosomes in an embryo with tetraploidy

“…To the best of our knowledge, the former has been reported only in two previous cases (Surti et al, 1986) and the latter has never been reported. Detailed molecular analysis has been reported for a single case to date (Guc-Scekic et al, 2002) and the molecular analysis of a case with the rare karyotype 92,XXXY adds to the current knowledge in the field. …”

A brief look at the origin of tetraploidy

“…Fusion of two fertilized eggs is the second alternative mentioned by Guc-Scekic et al (2002). One may speculate that this event would happen preferentially in oocytes enclosed within a common zona pellucida.…”

“…One alternative for explaining tetraploidy in a 26-monthold girl with the karyotype 92,XXXX is dispermic fertilization of a diploid egg that resulted from meiotic non-disjunction (Guc-Scekic et al, 2002). Also, the spontaneously aborted embryo examined by Baumer et al (2003) has been attributed to dispermy and a meiosis I error in the oocyte.…”

Totipotency: What It Is and What It Is Not

“…However, fully tetraploid mice frequently complete embryogenesis, and occasionally survive to live birth (reviewed in Eakin and Behringer [32]). Similarly, there are reports of live-born, tetraploid humans [33,34], although mosaicism …”

“…mES lines were first isolated in 1981 [82,83]. Yet, despite thousands of In most cases, the tetraploid embryo produces only TE derivatives, although live-born tetraploid mice [192] and humans [33,34] have been reported. Injection of diploid pluripotent stem cells at the blastocyst stage complements this defect, with stem cells producing most of the postnatal structures.…”