Outcome of fetuses with Turner syndrome: a 10-year congenital anomaly register based study.

OBJECTIVE: To describe the characteristics and outcome of fetuses with Turner syndrome reported to a national congenital anomalies register. METHODS: All cases with a diagnosis of Turner syndrome reported to Congenital Anomaly Register and Information Service for Wales (CARIS) between 1 January 1998 and 31 December 2007 were included. The cases were grouped in five categories based on their outcomes: fetal loss (FL), termination of pregnancy (TOP), live birth (LB), and postnatal (PN) detection and comparison was undertaken between the groups. RESULTS: One hundred twenty-four cases were reported during the study period. The prevalence of Turner syndrome was 1 in 4901 live female births. Seventy-four percent had 45 X karyotype while the rest had some form of Mosaic Turner karyotype. Pregnancy was terminated in 66% of antenatally diagnosed cases. FL and TOP groups had 92% and 87%, respectively, of 45 X karyotype - far greater than in the LB and PN groups. Increased nuchal thickness was the commonest anomaly noted in antenatal ultrasound and was a predictor for 45 X karyotype, FL, and termination. CONCLUSION: Termination was the most common outcome of fetuses diagnosed antenatally with Turner syndrome. This has modified the natural history of Turner syndrome particularly in cases with Mosaic karyotype.

Identification and clonal characterisation of a progenitor cell sub-population in normal human articular cartilage.

BACKGROUND: Articular cartilage displays a poor repair capacity. The aim of cell-based therapies for cartilage defects is to repair damaged joint surfaces with a functional replacement tissue. Currently, chondrocytes removed from a healthy region of the cartilage are used but they are unable to retain their phenotype in expanded culture. The resulting repair tissue is fibrocartilaginous rather than hyaline, potentially compromising long-term repair. Mesenchymal stem cells, particularly bone marrow stromal cells (BMSC), are of interest for cartilage repair due to their inherent replicative potential. However, chondrocyte differentiated BMSCs display an endochondral phenotype, that is, can terminally differentiate and form a calcified matrix, leading to failure in long-term defect repair. Here, we investigate the isolation and characterisation of a human cartilage progenitor population that is resident within permanent adult articular cartilage. METHODS AND FINDINGS: Human articular cartilage samples were digested and clonal populations isolated using a differential adhesion assay to fibronectin. Clonal cell lines were expanded in growth media to high population doublings and karyotype analysis performed. We present data to show that this cell population demonstrates a restricted differential potential during chondrogenic induction in a 3D pellet culture system. Furthermore, evidence of high telomerase activity and maintenance of telomere length, characteristic of a mesenchymal stem cell population, were observed in this clonal cell population. Lastly, as proof of principle, we carried out a pilot repair study in a goat in vivo model demonstrating the ability of goat cartilage progenitors to form a cartilage-like repair tissue in a chondral defect. CONCLUSIONS: In conclusion, we propose that we have identified and characterised a novel cartilage progenitor population resident in human articular cartilage which will greatly benefit future cell-based cartilage repair therapies due to its ability to maintain chondrogenicity upon extensive expansion unlike full-depth chondrocytes that lose this ability at only seven population doublings.