International perspectives on the implementation of reproductive carrier screening.

Reproductive carrier screening started in some countries in the 1970s for hemoglobinopathies and Tay-Sachs disease. Cystic fibrosis carrier screening became possible in the late 1980s and with technical advances, screening of an ever increasing number of genes has become possible. The goal of carrier screening is to inform people about their risk of having children with autosomal recessive and X-linked recessive disorders, to allow for informed decision making about reproductive options.

Preconception and prenatal genetic counselling.

Identifying individuals at risk of having children affected by genetic conditions or congenital anomalies allows counselling that aims to inform reproductive decisions. This process takes place either at the preconception or early prenatal stage, although more options are available if risks are identified before the pregnancy. Preconception counselling covers issues that can affect the health of the mother and baby including folic acid supplementation.

Foregut separation and tracheo-oesophageal malformations: the role of tracheal outgrowth, dorso-ventral patterning and programmed cell death.

Foregut division-the separation of dorsal (oesophageal) from ventral (tracheal) foregut components-is a crucial event in gastro-respiratory development, and frequently disturbed in clinical birth defects. Here, we examined three outstanding questions of foregut morphogenesis. The origin of the trachea is suggested to result either from respiratory outgrowth or progressive septation of the foregut tube.

Genetic testing in other GI diseases.

Gastrointestinal development is a complex process comprising folding of the endodermal layer to form the primitive gut tube, cell differentiation along its anteroposterior axis, the budding of the various organ primordia and development of derivative organs like the liver and pancreas and the colonisation of the gut with neuronal precursors. Genetic factors are increasingly recognised as playing a significant role in the disturbance of this developmental process which underlies congenital malformations and gastrointestinal disorders. Furthermore, genetic variation and its interaction with environmental influences play an important role in the pathogenesis of functional gastrointestinal disorders.

Embryology of oesophageal atresia.

Esophageal atresia (OA) and tracheoesophageal fistula (TOF) are important human birth defects of unknown etiology. The embryogenesis of OA/TOF remains poorly understood, mirroring the lack of clarity of the mechanisms of normal tracheoesophageal development. The development of rat and mouse models of OA/TOF has allowed the parallel study of both normal and abnormal embryogenesis.

Pouch-anal anastomosis vs straight ileoanal anastomosis in pediatric patients: a meta-analysis.

Background: Restorative proctocolectomy is the treatment of choice for pediatric patients with refractory colitis, inherited polyposis syndromes, and some with colonic aganglionosis. Evidence concerning the optimal method of reconstruction is, however, sparse.

Methods: Studies comparing outcomes from ileal pouch-anal anastomosis (IPAA) and straight ileoanal anastomosis (SIAA) were identified by searching Medline, Ovid, and Embase.

Role of Sonic hedgehog in the development of the trachea and oesophagus.

Background/purpose: The secreted glycoprotein, Sonic hedgehog (Shh) plays an important patterning role in the development of many organ systems. The authors aimed to study the temporal and spatial pattern of expression of Shh and its receptor Ptc1 during the development of the anterior foregut and to test the hypothesis that the Shh expression pattern is disturbed during the development of oesophageal atresia (OA) and tracheo-oesophageal fistula (TOF) in Adriamycin-treated mouse embryos.

Methods: Saline and Adriamycin-treated (4 mg/kg) CBA/Ca embryos were harvested between embryonic days (E) 10.

Dorsoventral patterning in oesophageal atresia with tracheo-oesophageal fistula: Evidence from a new mouse model.

Background/purpose: The well-established Adriamycin rat model of oesophageal atresia (OA) and tracheo-oesophageal fistula (TOF) complements recently described mouse genetic models in which loss of function mutations in foregut patterning genes, such as Nkx2.1 (Ttf 1), lead to OA/TOF. The authors aimed to integrate the 2 systems by adapting the Adriamycin model to the mouse to study molecular aspects of tracheo-oesophageal development.