Cornelia de Lange syndrome (Brachmann–De Lange Syndrome) Synophrys, Thin Downturning Upper Lip, Micromelia The syndrome was originally reported in 1933 by Cornelia de Lange, although Brachmann described a child with similar features at autopsy in 1916. As the molecular etiology…
1p36 Deletion Syndrome (Monosomy 1p36 Deletion Syndrome) Large Anterior Fontanel, Deep-Set Eyes, Pointed Chin First delineated in 1997 as a recognizable pattern of malformation, monosomy 1p36 is the most commonly observed terminal deletion in the human population with an estimated…
Chromosomal Abnormality Syndromes Identifiable on Routine Karyotype Down Syndrome (Trisomy 21 Syndrome)Hypotonia, Flat Facies, Slanted Palpebral Fissures, Small Ears Down’s report in 1866 on the ethnic classification of idiots stated that a “large number of congenital idiots are typical Mongols,”…
Rather simple principles apply for the role of mechanical factors in morphogenesis. These are that the direction and magnitude of forces affect the form of the developing individual, as illustrated in Fig. 51-1 . Some of the factors that affect…
Genesis The underlying mechanism for most defects related to problems associated with obstetric procedures is vascular disruption. With chorionic villus sampling (CVS), removal of villi may result in embryonic hypotension, hypoxia, endothelial damage, hemorrhage, and necrosis with tissue loss. Defects…
Genesis Constraint that occurs during the latter period of gestation can cause molded deformations with good prospects for spontaneous or assisted return to normal form; however, when constraint occurs during early morphogenesis, it can have more severe and lasting impacts…
Genesis Ectopic pregnancy , defined as the implantation of a fertilized ovum outside the uterus, occurs most commonly in the fallopian tube (95.5% of all ectopic pregnancies), with 70% implanting in the ampulla, 12% in the isthmus, 11% in the…
Genesis Fetal movement is essential to normal joint morphogenesis. Joints develop secondarily within the condensed mesenchyme of the developing bones, and chronic lack of movement leads to joint contractures. Fetal akinesia is associated with a specific combination of clinical findings…
Genesis The relative and absolute amount of amniotic fluid tends to decrease during the last trimester as the fetus fills out the uterine cavity, as shown in Fig. 46-1 . A serious deficiency of amniotic fluid will result in significant…
Genesis Several different types of problems can limit the size and/or shape of the uterus and thus enhance the likelihood of fetal deformation. Examples include a malformed uterus caused by failure of the Müllerian ducts to completely fuse during embryogenesis,…