Denouement and Discussion
Trisomy 18 (Edwards' Syndrome)
Manifestations
Major manifestations include failure to thrive, marked mental-motor retardation, classical facial appearance, cardiac and skeletal abnormalities, and an extra No. 18 chromosome. The facial characteristics are quite typical and consist of a Grecian nose, somewhat small palpebral fissures, ptosis of the eyelids, epicanthal folds, microphthalmia, low-set and malformed ears, high arched or cleft palate, micrognathia, and prominent occiput. Skeletal findings include a short sternum, flexion deformities of the fingers with the second finger overlapping the third and occasionally the fifth finger overlapping the fourth, retroflexed and distally placed thumb, ulnar deviation of the hands, small pelvis, limitation of motion of abduction of the hips, and rocker bottom feet. These patients are severely retarded and are usually hypertonic. The congenital heart abnormalities vary, with ventricular septal defect most frequently found. The dermatoglyphics are abnormal with an increased number of arches. Other findings include