* Department of Gynecology, Félix Guyon'Hospital **Department of Neonatology, Félix Guyon'Hospital *** Department of Obstetric, Hospital de Saint Pierre,  Ile de la Réunion, France

Definition: Congenital chloride diarrhea is a rare specific congenital defect of ileal chloride transport. The result is persistent osmotic diarrhea. Maternal polyhydramnios, abdominal distension, watery diarrhea and a high fecal chloride level > 90 mmol/l are the major features in the neonatal period.

Case Report: This is a 20-year-old-primigravida. The two parents have a consanguineous history. The first trimester screening was normal. The second scan was also normal. At 32 weeks, the patient had some uterine contractions and a scan was performed and revealed some intestinal abnormalities and a polyhydramnios. An amniocentesis was performed to request a karyotype and also for uterine decompression. At 33 weeks, a moderate polyhydramnios was present. The fetus had regular dilated, fluid filed and with few contracting small bowels in the whole abdomen. The stomach seemed compressed by a small bowel dilatation. There was a unilateral hydrocele without repercussion.

Unfortunately, the patient delivered vaginally at 33 weeks. The baby was female with a slightly distended abdomen. Abdominal and contrast colon radiographs were normal. The passage of meconium was not observed initially. There was no vomiting, but an abdominal distension. At day 2, the baby had loss watery stools. The baby had metabolic alkalosis and abnormal laboratory variables (serum Na+, 102 mmol/l, Serum K+, 2,5 mmol/l and serum Cl = mmol/l. Further investigation discovered a fecal concentration of Na+ (25 mmol/l), K+ (48 mmol/l), and Cl- (46 mmol/l).

The previous and following findings were suggestive of a congenital chloride diarrhea:

• polyhydramnios

• normal radiographic findings

• no vomiting, no passage of meconium and normal stools

• abdominal distension

• hyperbilirubinemia, hyponatremia, hypokalemia and hypochloremic and metabolic alkalosis.
  
  

This was confirmed by the high fecal chloride concentration. Few days later, we received the amniocentesis results (normal karyotype). But chloride levels were high.


Note the small bowel dilatation

The unilateral hydrocele and the deviation of the stomach

Polyhydramnios

History: Congenital chloride diarrhea was first described in Finland in 1945 and has most often been seen in this country and in Kuwait.

Prevalence: Congenital chloride diarrhea is a rare disorder, reported mainly in Finland. It is a recessive inherited disorder of chloride transport in the distal ileum and colon. It is a common disorder in Kuwait with an incidence of 1/3200 due to a high prevalence of consanguinity marriages in that country.

Etiology: Anomaly of chloride transport in the distal ileum and colon, and that is why there is a polyhydramnios and intestinal distention, during intra-uterine period.

Pathogenesis: Congenital chloride diarrhea is autosomal recessive disorder of intestinal Cl/HCO3 exchange caused by mutations in the SLC26A3 gene and it is characterized by a persistent chloride diarrhea after birth. The underlying defect is in chloride reabsorption by cells of the intestinal mucosa, associated with impaired transport of bicarbonate. The result is water diarrhea in utero and polyhydramnios, commonly leading to premature delivery. After birth, the infants become hypochloremic, hyponatremic, hypokalemic and alkalotic.

Ultrasound findings: In spite of the classical features of the disease, 75% of the Kuwait cases are diagnosed beyond the neonatal period and all demonstrated chronic diarrhea and failure to thrive, with hypochloremia, hypokalemia and metabolic alkalosis. Nevertheless, the prenatal scan showed dilated intestinal loops with polyhydramnios, which suggested a congenital chloride diarrhea. The diagnosis is confirmed by a high fecal chloride level.

Implications for Targeted Examinations: When we observed the typical aspect of regular dilated intestinal loops, with polyhydramnios, we should think about the congenital chloride diarrhea diagnosis.

Differential Diagnosis:

• Ano-rectal atresia or imperforation: There is essentially dilatation of the colon. And polyhydramnios can be absent.

• Colon aganglionosis or Hirschsprung disease: There is a total absence of ganglion cells in both submucosal (Meissner's) and myenteric (Auerbach's) plexuses of the intestine. When the disease involves the ileum and, less often, the jejunum, the disease is call Jirasek-Zuelzer-Wilson disease.

• Intestinal occlusion: caused by anatomic anomalies (Meconial occlusion, intestinal stenosis, brides, etc.). Nevertheless, the dilated intestinal loops are not so regular and can be filled of meconium as in Mucoviscidosis.

Associated Anomalies: A fecal chloride concentration exceeding the sum of the sodium and potassium concentrations suggest the diagnosis. The condition may also be diagnosed antenatally. Ultrasound examinations may reveal a regular distension of intestinal loops after 25 weeks. Polyhydramnios with premature delivered is always present.

Prognosis: Unfortunately, there is no treatment to the diarrhea of congenital chloride diarrhea, but children with this condition become toilet trained at a normal age. Their social adjustment can be impaired, but the prognosis is good if potassium as well as sodium and chloride are replaced regularly.

Management: Treatment is usually symptomatic. Replacement therapy with NaCl and KCl has been shown to be effective, but the long-term prognosis remains unclear. Nevertheless, early diagnosis and aggressive salt replacement therapy were associated with normal growth and development, in addition to significancy reduced mortality rates. Enuresis, slight soiling and hospitalization for gastroenteritis are common, especially during early childhood. Complications can be end-stage renal disease, hyperuricemia, infertility, spermatoceles, intestinal inflammation, inguinal hernias and increased concentrations of sweat Cl.

References:

1- Badawi M.H., Zaki M., Ismail E.A., Majid Molla A.- Congenital chloride diarrhoea in Kuwait : a clinical reappraisal. J Trop Pediatr 1998 ; 44 : 296-9.
2- Contreras M., Rocca A., benedetti L., Kakisu H., Delgadoi S., Ruiz J.A.- Congenital chloride diarrhoea
3- Hihnala S., Hoglund P., Lammi L., kokkonen J., Ormala T., Holmberg C.- Long term clinical outcome in patients with congenital chlorid diarrhea. J Pediatr gastro-enterol Nutr 2006 ; 4 : 36-45.
4- Norzila M.Z., Azizi B.H.- Congenital chloride diarrhoea in a malay Child. Med J Malaysia 1994 ; 49 : 102-4.
5- Husu S., Nelson N., Selbing A.- Prenatal bowel dilatation : Congenital chloride diarrhoea. Arch Dis Child Neonate Ed 2001 ; 85 : F65.
6- Rowlands S., Kasby C., Poon C., Murray H.- Antenatal ultrasound diagnosis of dilated fetal bowel due to congenital chloride diarrhea. Aust N Z Obstet Gynaecol 1996 ; 36 : 366-8.