Monozygotic twins with petal akinesia: The importance of clinicopathological work-up in predicting risks of recurrence

Fetal Akinesia Deformation Sequence (FADS) or Pena-Shokeir Sequence is a he terogeneous group of disorders in which prolonged decrease or absence of fe tal movements results in a series of deformational anomalies: multiple cont ractures, pulmonary hypoplasia, craniofacial anomalies, polyhydramnios, int rauterine growth retardation, and short umbilical cord. Three sets of monoz ygotic twins, and their affected sibs, are presented. Detailed pathological work-up established that the two pairs of twins concordant for FADS were o f myogenic etiology while the set discordant was due to anoxic-ischemic dam age. In the myogenic cases, the rate of recurrence was high, in agreement w ith the findings from the study on arthrogryposis multiplex congenita of my ogenic origin [22]. In light of these findings, in sporadic cases of myogen ic FADS, counselling, a recurrence risk of 25% seems prudent. In neurogenic cases associated with primary cerebral malformations, there are cases cite d in the literature that are clearly recessive as indicated by affected sib s, but many reported are isolated occurrences. Therefore, in this scenario, giving a recurrent risk of 10-15% appears appropriate. In light of autosom al recessive spinal muscular atrophy and reports of familiar FADS due to pr imary anterior horn cell loss, counselling a 25% risk seems prudent. In cas es due to anoxic-ischemic damage, offering a low recurrent risk of 1% appea rs justified.