Prune belly syndrome
|Prune belly syndrome|
Prune belly syndrome in an Egyptian child with Down syndrome.
|Classification and external resources|
Prune belly syndrome, also referred to as abdominal muscle deficiency syndrome, congenital absence of the abdominal muscles, Eagle-Barrett syndrome, Obrinsky syndrome, Fröhlich syndrome, or, rarely, triad syndrome, is a rare, genetic birth defect affecting about 1 in 40,000 births. About 97% of those affected are male. Prune belly syndrome is a congenital disorder of the urinary system, characterized by a triad of symptoms. The syndrome is named for the mass of wrinkled skin that is often (but not always) present on the abdomen of those with the disorder.
- A partial or complete lack of abdominal wall muscles. There may be wrinkly folds of skin covering the abdomen.
- Cryptorchidism (undescended testicles) in males
- Urinary tract abnormality such as unusually large ureters, distended bladder, accumulation and backflow of urine from the bladder to the ureters and the kidneys (vesicoureteral reflux)
- Frequent urinary tract infections due to the inability to properly expel urine.
- Later in life, a common symptom is post-ejaculatory discomfort. Most likely a bladder spasm, it lasts about two hours.
- Ventricular septal defect
- Malrotation of the gut
- Club foot
Prune belly syndrome can be diagnosed via ultrasound while a child is still in-utero. An abnormally large abdominal cavity resembling that of an obese person is the key indicator, as the abdomen swells with the pressure of accumulated urine. In young children, frequent urinary tract infections often herald prune belly syndrome, as they are normally uncommon. If a problem is suspected, doctors can perform blood tests to check renal function. Another study that may suggest the syndrome is a voiding cystourethrogram.
PBS is far more common in males. Autosomal recessive inheritance has been suggested in some cases. A homozygous mutation in the muscarinic cholinergic receptor-3 gene (CHRM3) on chromosome 1q43 was reported in one family.
Prune belly syndrome can result in distention and enlargement of internal organs such as the bladder and intestines. Surgery is often required but will not return the organs to a normal size. Bladder reductions have shown that the bladder will again stretch to its previous size due to lack of muscle. Complications may also arise from enlarged/malformed kidneys, which may result in renal failure and the child's going on dialysis or requiring a kidney transplant. With proper treatment, however, a longer, healthier life is possible.
Musculoskeletal abnormalities include pectus excavatum, scoliosis, and congenital joint dislocations including the hip. Diagnosis of prune belly syndrome necessitates a thorough orthopaedic evaluation because of the high prevalence of associated musculoskeletal abnormalities.
The type of treatment, like that of most disorders, depends on the severity of the symptoms. One option is to perform a vesicostomy, which allows the bladder to drain through a small hole in the abdomen, thus helping to prevent urinary tract infections. Similarly, consistent self catheterization, often several times per day, can be an effective approach to preventing infections. A more drastic procedure is a surgical "remodeling" of the abdominal wall and urinary tract. Boys often need to undergo an orchiopexy, to move the testes to their proper place in the scrotum.
- Eagle JF, Barrett GS (1950). "Congenital deficiency of abdominal musculature with associated genitourinary abnormalities: A syndrome. Report of 9 cases". Pediatrics. 6 (5): 721–36. PMID 14797335.
- Obrinsky W (1949). "Agenesis of abdominal muscles with associated malformation of the genitourinary tract; a clinical syndrome". Am J Dis Child. 77 (3): 362–73. doi:10.1001/archpedi.1949.02030040372008. PMID 18116668.
- Frolich, F. Der Mangel der Muskeln, insbesondere der Seitenbauchmuskeln. Dissertation: Wurzburg 1839.
- Baird PA, MacDonald EC (1981). "An epidemiologic study of congenital malformations of the anterior abdominal wall in more than half a million consecutive live births". Am. J. Hum. Genet. 33 (3): 470–8. PMC . PMID 6454342.
- synd/1499 at Who Named It?
- Brinker MR, Palutsis RS, Sarwark JF 1995. The orthopaedic manifestations of prune-belly (Eagle-Barrett) syndrome. J Bone Joint Surg Am. 77(2):251-7