Early fetal akinesia deformation sequence: A case report with unusual autoptic features

Abstract

In this paper we report a case of early onset fetal akinesia, with unusual pathological findings. This is a product of medical abortion of young, healthy, unrelated parents. The mother's obstetrical history revealed two previous early miscarriages and a suspicion of FADS in the second previous gestation. At 17 weeks of gestation, an ultrasound examination disclosed absence of fetal movements, fixed extended knees and deformation of the feet. Amniocentesis showed a normal 46, XX karyotype. Hydrops fetalis and multiple skin webs (pterygia), which are usually present in cases of early fetal akinesia, were absent. A diagnosis of arthrogryposis was made and the pregnancy was terminated at 17 weeks of gestation. Postmortem examination was performed according to the necropsy technique suggested by Langley. Thus, body weight and external measurement, including crown-rump, crown-heel, foot lengths, head, thorax and abdominal circumferences were estimated and compared with standard values for assessment of fetal growth. External dysmorphic features were evaluated prior to the evisceration. On internal examination the location and shape of every organ was evaluated. Every organ, skin, muscles from different parts of the body, the brain and spinal cord were sampled and histologically examined. External examination revealed a female fetus with marked muscular hypoplasia of upper and lower extremities with thin arms and legs and multiple joint contractures of lower extremities. The face showed a flattened nose, micrognatia, hypertelorism, cleft palate and low-set ears. There was also a small nuchal fold. The abdomen was distended with a very thin and almost transparent wall. Histologically, muscles were characterized by severe fibrosis with fatty infiltration and by moderate variability in diameter of muscle fibers. The spinal cord disclosed a paucity of anterior horn motor neurons. We suggest multiple pterygium as a diagnosis. Lethal multiple pterygium syndrome (LMPS) is only a symptom and the precise diagnosis is more likely to be spinal atrophy. We, moreover believe that the paucity of spinal motoneurons could be due to the anomalies of programmed death during fetal development and the consequence of genetic defects.