Long-term clinical outcome in patients with congenital chloride diarrhea

Congenital chloride diarrhea (CLD) is a rare, autosomal recessive disorder of intestinal Cl/HCO3 exchange caused by mutations in the SLC26A3 gene and characterized by persistent Cl rich diarrhea from birth. Treatment is symptomatic and replacement therapy with NaCl and KCl has been shown to be effective in children, but the long-term prognosis remains unclear. We studied the largest known cohort of patients to evaluate the long-term outcome of CLD and to search for extraintestinal manifestations.

This is a cross-sectional clinical evaluation and retrospective analysis of medical history of 36 Finnish patients with CLD, born in the 1960s (n = 8), 1970s (n = 7) and 1980s (n = 21).

Early diagnosis and aggressive salt replacement therapy were associated with normal growth and development, in addition to significantly reduced mortality rates among the groups of patients born in the different decades, respectively (P = 0.001). No deaths due to CLD were observed after 1972. Enuresis, slight soiling and hospitalizations for gastroenteritis were common, especially in childhood, but 92% of the patients found their health excellent or good. Complications documented were end-stage renal disease (n = 1) and hyperuricemia (n = 4), novel findings possibly associated with CLD being male subfertility (n = 3), spermatoceles (n = 3), intestinal inflammation (n = 2), inguinal hernias (n = 4) and increased concentrations of sweat Cl in 12% of the patients.

When early diagnosed and adequately treated, the long-term prognosis of CLD is favorable. A putative role of a primary anion exchange defect of SLC26A3 in male subfertility and the decline of renal function due to chronic dehydration deserve further characterization.