The T-box transcription factor BRACHYURY (T) is a key regulator of mesoderm formation during early development. Complete loss of T has been shown to lead to embryonic lethality around E10.0. Here we characterize an inducible miRNA-based in vivo knockdown mouse model of T, termed KD3-T, which exhibits a hypomorphic phenotype. KD3-T embryos display axial skeletal defects caused by apoptosis of pa...

C audal regression syndrome (CRS) is a rare embryopathy characterized by maldevelopment of the vertebrae, visceral organs, and lower extremities. Patients with CRS have deformities of the sacrococcygeal vertebrae and develop neurogenic bladder from dysfunction of the sacral nerve root. Additional anomalies include congenital heart defects, intestinal malrotation, agenesis of the genitourinary s...

Caudal regression syndrome (CRS) is a malformation occurring during the fetal period and mainly characterized by an incomplete development of the spinal cord (SC), which is often accompanied by other developmental anomalies. We studied a 9-month old child with CRS who presented interruption of the SC at the L2-L3 level, sacral agenesis, a lack of innervation of the inferior limbs (flaccid parap...

If the mermaid legend evokes more of mythology than of pathology, its origin very probably lies in ancient observations of certain types of human monstrosities. Human sirens are not as rare as is sometimes thought; I have been able to examine two cases within the past year, and during that time I have been told of several others. I shall talk today of the usual findings and attempt to draw cert...

audal regression syndrome (CRS) represents a continuum of congenital anomalies that may include incomplete development of the sacrum and, to a lesser extent, the lumbar vertebrae, disruption of the distal spinal cord, and extreme lack of growth of the caudal region.1 First-trimester prenatal diagnosis of CRS is challenging because of incomplete ossification of the sacrum at that time.2 Most cas...