Prenatal diagnosis of Pena-Shokeir syndrome type 1

Pena-Shokeir phenotype (fetal akinesia deformation sequence) revisited

BACKGROUND

Pena and Shokeir described the phenotype of two sisters in 1974, and subsequently their features have become recognized as a sequence of deformational changes related to decreased or absent fetal movement (fetal akinesia deformation sequence [FADS]), because of the work of Moessinger (1983).

METHODS

Identification of reported cases by searching Online Mendelian Inheritance in Man, Medlines, the London Dysmorphology Database, and the references found in these articles. These case reports were reviewed, tabulated, and summarized.

RESULTS

It is now possible to recognize at least 20 familial types of Pena-Shokeir phenotype (PSP), based on the differences found in the reports of the natural history and pathology found at fetal and newborn autopsy. In addition, characteristic changes in the central nervous system seen with embryonic/fetal vascular compromise have been recognized in many reported cases. Most of the reported cases of PSP/FADS related to vascular compromise are sporadic, but familial cases have also been reported.

CONCLUSION

Lack of fetal movement (fetal akinesia) in humans produces a recognizable sequence of deformations. Many developmental processes must be accomplished for fetal movement to be normal, and for extra-uterine life to be sustainable. Prenatal diagnosis is possible through real-time ultrasound studies as early as 12 weeks. Most reported cases die in utero, at birth, or in the newborn period. Advances in embryo/fetus pathology have led to the recognition of the many familial subtypes, allowing improved genetic counseling and early recognition in subsequent pregnancies.

Multiple congenital contractures (congenital multiple arthrogryposis)

Arthrogryposis, is the occurrence of joint contractures of variable etiology that start prenatally. Arthrogryposis may result from neurologic deficit, neuromuscular disorders, connective tissue abnormalities, amniotic bands, [figure: see text] or fetal crowding. Arthrogryposis may result from no apparent hereditary causes (neuropathic, for example) or may be the result of hereditary factors (myopathic form, for example). Ultrasound diagnosis depends on observation of scant or absent motion of fetal extremities. Prognosis depends on the specific etiology of the contractures.

Hydrops fetalis: recent advances

Hydrops fetalis is a morbid condition caused by a wide variety of fetal, placental, and maternal diseases. Mortality is high and depends on the gestational age at the time of occurrence and underlying etiology. Although the condition was described more than 300 years ago, recent advances in obstetric ultrasound, prenatal diagnostics have made it possible to differentiate various etiologies involved. It is also possible to treat some of these fetuses prenatally. In utero medical and surgical therapy is presently done in some centers. However, the majority of cases diagnosed remain untreatable. Early diagnosis of untreatable cases allows parents to make informed choices about subsequent management. Recent advances are covered in this review.

The significance of ultrasonographically diagnosed fetal wrist position anomalies

OBJECTIVE

Our purpose was to determine the clinical significance of ultrasonographically diagnosed fetal wrist position anomalies.

STUDY DESIGN

The relationship of the fetal hand to the forearm was prospectively evaluated in all second- and third-trimester scans over a 5-year period. If an abnormal wrist position was detected, a targeted scan, including echocardiography, was performed. The outcomes of abnormal pregnancies were obtained.

RESULTS

An abnormal relationship of the hand to the forearm was found in 22 fetuses in 27,467 scans. Nine had a normal karyotype, and 13 had an abnormal karyotype. Among the nine with normal chromosomes, three had evidence of a movement disorder. Three with normal karyotypes are alive; two of these are the only normally functioning survivors. They had no other major anomalies and were shown prenatally to have normal movement of the limbs.

CONCLUSIONS

An abnormal fetal wrist position is associated with a high incidence of karyotype and movement abnormalities.

Ultrasound diagnosis of the Pena Shokeir phenotype at 14 weeks of pregnancy

This report describes the early prenatal diagnosis of the Pena Shokeir phenotype in an at-risk patient at 14 weeks' gestation. The diagnosis was based on an abnormal fetal movement profile, in association with an abnormal position of the fetal limbs. Pena Shokeir phenotype describes an inherited condition characterized by arthrogryposis and dysmorphic features as a result of fetal akinesia. It is a lethal abnormality and early diagnosis allows safer surgical methods of termination.

Fetal akinesia

Normal fetal growth and development during pregnancy is highly dependent upon adequate fetal movement. Limitation of movement, regardless of the underlying cause, can result in a particular pattern of abnormal fetal morphogenesis. This phenotype is termed the fetal akinesia deformation sequence (FADS). The etiology of fetal akinesia may be generally classified into one of five categories: neuropathy, myopathy, restrictive dermopathy, teratogen exposure, or restricted movement due to intrauterine constraint. In this article, the differential diagnosis of fetal akinesia is systematically reviewed and information regarding prenatal diagnosis, prognosis, perinatal management, and recurrence risks are discussed.

Fetal akinesia/hypokinesia sequence: prenatal diagnosis and intra-familial variability

Intrauterine fetal movement plays a key role in normal embryonic and fetal development (Moessinger, 1983). When movement is absent or decreased, abnormal development takes place which can be appreciated in newborns and/or fetuses with the fetal akinesia/hypokinesia sequence. This sequence is caused by a number of heterogeneous entities which result in decreased fetal movements by the action of intrinsic or extrinsic factors. Prenatal diagnosis of the akinesia/hypokinesia sequence may be possible during the second trimester through the use of real-time ultrasonographic evaluation of fetal movement. We report a family with three consecutive affected pregnancies in which the prenatal presentation of this sequence varied. Based on the phenotypic findings of the three affected fetuses, we believe that although they superficially resemble those features found in the New-Laxova syndrome, they are probably affected with a distinctly different lethal form of akinesia/hypokinesia transmitted in an autosomal recessive fashion.

Skeletal muscular changes in Pena-Shokeir sequence

Histologic examination of the skeletal muscles in 8 fetuses and newborn patients with the Pena-Shokeir sequence revealed only minor nonspecific changes which could not be ascribed to any of the well defined myopathies. Muscle fiber diameters were increased in 2 out of 5 patients examined. No significant malformations of inner organs were found at autopsy. It is concluded that fetal hypokinesia due to skeletal muscular lesions might be responsible for both the pulmonary hypoplasia and the deformations of the face and extremities in all cases of this investigation.

Pena-Shokeir phenotype in sibs with macrocephaly but without growth retardation

A number of more or less distinct subgroups with the Pena-Shokeir phenotype have been identified. We studied two brothers with the Pena-Shokeir phenotype who were unusual because they had macrocephaly and normal growth. In the second sib, no neuromuscular abnormalities were found at autopsy. Among the subgroups with Pena-Shokeir phenotype, these sibs resemble the family reported by Ohlsson et al. [1988] more than the other subgroups that have been proposed. In addition, abnormalities were detected by prenatal ultrasonography during the 18th week of gestation of the second fetus. This finding provides additional evidence that this phenotype may be detected early enough in gestation to consider intervention.

Prenatal diagnosis of distal arthrogryposis

We report the prenatal diagnosis of distal arthrogryposis type I by ultrasound at 18 wk gestation in a family with two other affected members (mother and sister of the fetus). The pregnancy was followed with serial ultrasounds, and the diagnosis was confirmed after birth. The clinical findings in all affected family members are described. A literature survey of prenatally diagnosed cases of multiple joint contractures is presented. These include cases with many different diagnoses. This is the first report of the prenatal diagnosis of distal arthrogryposis type I. It helps to illustrate the variability and prenatal natural history of the condition and the subtlety of the prenatal ultrasound findings.

Prenatal sonographic diagnosis of Pena-Shokeir syndrome type I, or fetal akinesia deformation sequence

We report on a familial case of Pena-Shokeir syndrome type I (fetal akinesia deformation sequence) born to healthy parents. The antenatal ultrasound diagnosis was based on hydramnios, restricted limb movements, decreased fetal chest movements, small chest, arthrogryposis, clubfoot, fixed extension of knees, fixed flexion of elbows, camptodactyly, kyphosis of thoracic spine, cryptorchidism, and small muscle bulk. Thymic hyperplasia was noted at autopsy.

Prenatal diagnosis of a new syndrome: holoprosencephaly with hypokinesia

Markedly decreased fetal activity (akinesia/hypokinesia) is usually readily apparent to experienced mothers, and frequently this concern leads to attempts at prenatal diagnosis. We report prenatal diagnosis of two fetuses with congenital contractures, markedly decreased fetal movement, and microcephaly due to severe holoprosencephaly. Such familial recurrence to phenotypically normal parents suggests a newly recognized autosomal recessive or X-linked syndrome that is readily detectable by prenatal ultrasonography.

Prenatal ultrasonographic features of the Pena-Shokeir I syndrome and the trisomy 18 syndrome

The prenatal ultrasonographic features found in two cases each of the Pena-Shokeir I and the trisomy 18 syndromes are described. All four cases were referred for ultrasonographic evaluation of polyhydramnios, clinically detected in the third trimester. A detailed ultrasonographic study of the craniofacial structures, intrathoracic organs, and limbs showed scalp edema, multiple ankyloses, camptodactyly, rocker-bottom feet, cardiac arrhythmias, and lung hypoplasia. Chromosome analysis showed trisomy 18 in two cases; in the other two cases the diagnosis of the Pena-Shokeir I was confirmed after delivery. The similarity of the two syndromes with respect to ultrasound findings is discussed.

Analysis of Pena Shokeir phenotype

At this point in time, we recognize that "Pena Shokeir" is not a diagnosis or a specific syndrome but rather a description of a phenotype produced by fetal akinesia or decreased in utero movement. In its "full blown" form, it is characterized by polyhydramnios, intrauterine growth retardation, pulmonary hypoplasia, craniofacial and limb anomalies, congenital contractures, short umbilical cord, and lethality. From the cases thus far reported, we would anticipate that the phenotype is present in a very heterogeneous group of disorders--heterogeneous both with regard to the specific anomalies present and with regard to the causes (which must include many environmental agents and multiple genetic forms). One challenge for the future is to better describe and delineate specific entities. In the meantime, we would do well to use the terms "Pena Shokeir phenotype" or "fetal akinesia/hypokinesia sequence," which do not imply a single entity. There are many practical aspects of recognizing this phenotype. The presence of any one of the cardinal signs of the fetal akinesia/hypokinesia sequence should alert the physician to look for the other associated anomalies, since specific treatment may be indicated, and catch-up or compensatory growth may occur, if given a chance. The ability to provide prenatal diagnosis and perhaps prenatal treatment in the future may allow us to alter dramatically the natural history of some cases. In others, we need to establish when treatment is possible and when it gives no benefit. Perhaps the most important insight gained from the study of the fetal akinesia sequence is the reaffirmation of the concept that function is an integral part of normal development. Specific structures do not develop in isolation but are part of a carefully timed and integrated system. The "use" of a structure in utero is necessary for its continuing and normal development. The old adage "use it or lose it" seems to apply just as appropriately to prenatal normal development as it does in the crusty adult world of politics, business, and academia.