Prune-belly syndrome is characterized by a triad of abnormalities that include, absence of the lower portion of the rectus abdominis muscle and the inferior and midportions of the oblique muscles (causing the skin of the abdomen to wrinkle like a prune), undescended testicles, an expanded bladder and problems in the upper urinary tract, which may include the bladder, ureters, and kidneys. Prognosis may vary from death in utero to a near-normal life expectancy. Prune-belly anomalies are rare and occur mostly in boys. Males suffering from PBS have been noted to be sterile. Several cases have been reported in girls (incomplete prune-belly syndrome) but usually with milder symptoms.
Absence of abdominal muscles with urinary tract abnormality and cryptorchidism is caused by homozygous mutation in the CHRM3 gene. The M3 cholinergic receptor mediates autonomic neurotransmission in the ocular iris pupillary sphincter and the detrusor muscle in humans.
Afifi et al.(1972) described a patient affected with prune-belly syndrome born to first-cousin parents.
Rajab et al. (1996) conducted a retrospective study to determine the incidence and effects of genetic and environmental factors on posterior urethral valves (PUV) in Oman. Between 1987 and 1994, 84 Omani individuals with PUV were referred to the pediatric surgery unit in the Royal Hospital for management. The calculated incidence of PUV by using this data was 1 in 2375 males, which was higher than that reported in UK. Upon analyzing the dates of conception of these children, no seasonal variation was detected. On the other hand, this study showed marked regional variation with the highest incidence in Muscat (1 in 2000 males) and Dakhilya (1 in 1700 males) while the lowest incidence was seen in Dhofar. Out of the 47 families in which information about consanguinity was available, consanguinity was present in 87% of the parents, with 54% being first cousins, 11% were second cousins and 24% of the parents were from the same tribe. In 34% of the 84 children, other congenital anomalies were detected, with the most common being genitourinary malformations in 17%, followed by gastrointestinal abnormalities in 9%, and spinal lesions in 7%. The segregation analysis with a p value of 0.013 suggested that autosomal recessive inheritance was not the causative factor of increased incidence of PUV in the Omani population. Rajab et al. (1996) recommended screening for male siblings of the affected patients to prevent irreversible renal deterioration and to use these data in further studies to determine the genetic factors predisposing to the malformation.
Sawardekar (2005) conducted a study to establish the prevalence of major congenital malformations in children born during a 10-year period in an Omani hospital in Nizwa. Of the 21,988 total births in the hospital, two children were born with Prune Belly Syndrome.
Akl and Zayyoud (1983) reviewed the medical records of 83 children who presented with renal disorders in Qatar during a single year. One patient with chronic renal failure was found to have the Prune Belly syndrome.
[Akl K, Zayyoud M. The spectrum of childhood kidney disease in Qatar. Qatar Med J. 1983; 4(2):95-7.}
Al Harbi (2003) described the first case of an infant (female) born with Down syndrome and prune-belly anomalies.
Boutheina et al. (2000) carried out prenatal diagnoses in 43 patients with lethal urinary tract abnormalities during a five-year-period. Meckel-Gruber syndrome and Prune-Belly syndrome were detected in 4% of the studied cases.
To establish the profile of major congenital malformations, Al Talabani et al. (1998) studied 24,233 consecutive births at Corniche hospital, Abu Dhabi, between January 1992 and January 1995. A total of 401 infants, including 289 of Arab origin, were detected with major malformations. Only one case of prune-belly syndrome was reported - in a infant born to first cousin parents from the United Arab Emirates. No recurrence was reported in the family.