Preaxial polydactyly of the foot: variable expression of trisomy 13 in a case from central Africa

Next-generation Sequencing and Karyotype Analysis for the Diagnosis of Robertsonian Translocation Type Trisomy 13: A Case Report

Trisomy 13 (Patau syndrome) is the third most common autosomal trisomy with a prevalence between 1 in 10,000 - 20,000 live births. Robertsonian translocations represent the largest number of chromosomal aberrations in human population with an incidence of 1.23 in 1000 live birth and translocation 13;14 is one of the most frequent Robertsonian translocations (approximately 75%). We sampled umbilical vein blood from a 27-yr-old woman whose ultrasonography findings revealed congenital heart defects, single ventricle, polycystic kidney, median cleft lip and palate and holoprosencephaly at gestational age of 23+6 weeks for karyotype and sequencing during intra-amniotic cavity injection of acrinol for labor induction. Next-generation sequencing indicated 47,XN,+13 and karyotype was identified as 46,XN,+13,rob (13;14). An unexpected problem becomes more and more obvious in human cytogenetics - it seems to become difficult to decide how and when to use the "molecular cytogenetics" or "traditional karyotype analysis". Molecular cytogenetics, such as next-generation sequencing and array-based comparative genomic hybridization (array-CGH), can detect microdeletions and micro-duplications, but it cannot detect balanced translocations. For this case, we cannot find balanced translocations by Molecular cytogenetics. The purpose of this case is that molecular cytogenetics cannot replace the traditional karyotype analysis, but can serve as a useful complement for G-banding to be used in the clinical cytogenetic diagnosis.

Sacrococcygeal teratoma in a female newborn with clinical features of trisomy 13: a case report from Central Africa

Introduction

The objective of this report is to describe the first patient presenting clinical features of trisomy 13 in association with a sacrococcygeal teratoma.

Case presentation

We present the case of a Congolese female infant born with bilateral cleft lip and palate, hypotelorism, microcephaly, and capillary hemangioma on her face. She presented with a large sacrococcygeal mass (15.0 cm ×12.0 cm ×5.0 cm) with a cystic consistency and a positive transillumination.

Conclusion

This observation suggests that overexpression of certain genes on chromosome 13 may lead to tumor formation from remnant cells of Hensen’s node.