NeurometPlus

Incidence

Autosomal recessive inheritance (with parental consanguinity and/or recurrence in sibs) has been implied in about 50% of the published cases. The syndrome is rare; about 100 cases were described in the literature.

Clinical Characteristics

The fetal akinesia/hypokinesia ( or Pena-Shokeir syndrome type I ) sequence includes multiple joint contractures, facial anomalies and pulmonary hypoplasia. Whatever the cause, the common of this sequence is decreased foetal activity. Failure of normal deglutition results in polyhydramnios, and a lack of movements of the diaphragm and intercostal muscles leads to pulmonary hypoplasia. The short umbilical cord and multiple joint contractures are due to lack of normal fetal movement. Ulnar deviation of hands, rocker-bottom feet, camptodactyly, sparse dermal ridges and absence of palmar flexion creases are the other components of the akinesia sequence. The face is expressionless, with hypertelorism, telecanthus, poorly folded, small, and posteriorly angulated ears, the mouth is small with micrognathia and high-arched palate. Cleft palate and cardiac defects may occur occasionally. Many of these babies are born prematurely, and even when born at term their growth is delayed, they have a short neck and a cryptorchidism. When surviving, they are likely to develop short-gut syndrome with malabsorption. There are similarities between Pena-Shokeir syndrome type I and the trisomy 18 syndrome: all may had multiple ankyloses, camptodactyly, and rocker-bottom feet. A karyotype will definitely permit differential diagnosis. The syndrome is rare; about 100 cases were described in the literature. About 30% are stillborn, and the majority of those live-born die of the complications of pulmonary hypoplasia. The Pena-Shokeir syndrome is not a unitary entity but is etiologically heterogeneous. Autosomal recessive inheritance (with parental consanguinity and/or recurrence in sibs) has been implied in about 50% of the published cases. Maternal myasthenia gravis has been diagnosed in some cases, and animal experiments show the curarization of the mother induces fetal akinesia. All plausible causes of foetal immobility should be searched for (myogenic, neurogenic, ischemic/anoxic), with biopsies when possible. This heterogeneity makes accurate recurrence risk counselling difficult. A 0.01 to 25% risk for recurrence seems most appropriate in apparently sporadic cases. Prenatal diagnosis after the birth of an index case relies on ultrasound, that shows polyhydramnios, ankyloses, scalp oedema, and decreased chest movements in the foetus with pulmonary hypoplasia.

Precipitants

None.

Provocation Tests

None.

Diagnostic Procedures

It is a clinical diagnosis. A karyotype will help differentiate from trisomy 18 syndrome