Prune Belly Syndrome

At a glance

Congenital absence of abdominal musculature leading to urinary and respiratory problems. Diagnosed based on a triad of (a) deficient abdominal wall musculature, (b) urinary tract dilatation, and (c) cryptorchidism. The major prognostic factor is the degree of dilation of the urinary tract.

Synonyms

Eagle-Barrett Syndrome; Abdominal Muscular Deficiency Syndrome; Triad Syndrome; Fröhlich Syndrome.

History

First described in 1839 by F. Fröhlich and the name “Prune-Belly Syndrome” was given by W. Osler in 1901. It was fully described by W. Obrinsky in 1949. G. S. Barrett and J. F. Eagle, Jr., American urologists, popularized this medical condition. The pathogenesis is not clearly understood. The triad (see “Diagnosis”) may arise simply from the effects of early urethral obstruction and distended bladder, or, alternatively, from a basic defect of the mesoderm. The full syndrome probably occurs only in males.

Incidence

Approximately 4:100,000 live births; male/female ratio of 20:1 (95% in males).

Genetic inheritance

Sporadic although autosomal recessive inheritance has been reported.

Pathophysiology

Familial Prune Belly Syndrome patients share a common homozygous mutation in the CHRM3 gene on chromosome 1q43. Other pathogenic theories include urethral obstruction and a mesodermal developmental defect. Dilation of the urinary tract in utero leads to secondary pressure atrophy of the abdominal wall and the subsequent clinical findings. However, the prevailing theory is the theory of mesodermal arrest, which would explain the involvement of the genitourinary tract, the testes, and the abdominal wall. A noxious insult would have to occur between the sixth and tenth weeks of gestation. It has been suggested that the embryogenesis of this disorder resides in the 3 weeks of development, which could also explain the prostatic hypoplasia and poor glandular development. The mesodermal arrest theory is supported by the histologic findings in the abdominal wall, the urinary tract, and the male genital system. The thinned abdominal wall has been attributed to hydronephrosis and the distended urinary system to interfering with normal descent of the testes. However, other patients with severe hydronephrosis may not show the same abdominal wall disorder. An insult to the mesodermal layer during the early stages of gestation should impact on other organ systems, which are not observed.

Diagnosis

Based on the triad of (a) deficient abdominal wall musculature, (b) urinary tract dilatation, and (c) cryptorchidism.

Clinical aspects

There is an absence of the muscles in ...