This document discusses chloride losing diarrhoea (CLD), a rare genetic condition caused by mutations in the SLC26A3 gene. It causes watery diarrhoea from birth and metabolic alkalosis due to excessive chloride loss. It can lead to dehydration, electrolyte abnormalities, and long-term complications affecting the kidneys and male fertility if not managed properly. Treatment involves oral and intravenous salt replacement therapy with sodium chloride and potassium chloride to prevent dehydration and metabolic alkalosis. Additional treatments including proton pump inhibitors, oral butyrate, and cholestyramine may help reduce diarrhoea. With prompt treatment and management of electrolyte losses, outcomes have improved from fatal to now treatable
2. Introduction
Rare
Difficult to diagnose and manage
AR inheritance
1945-Holmberg, Wedejoja et al- watery diarrhoea + high chloride
content of stool + metabolic alkalosis: “metabolic alkalosis with
diarrhoea” or “congenital chloridorrhea”
Finland 1960s- Finland- “CLD/ CCD”
genetic origin
Treatment
3. Incidence
• Kuwait- 1/3200 Single cases may appear world wide
• Saudi Arabia -1/5000 Mutation analysis –in low incidence countries
• Finland-1/30,000-40,000
• Poland -1/200,000
4. Pathophysiology
Function of chloride
Regulate cell volume
Fluid secretion
Acid base balance
Defect: SLC26A3 (solute carrier
protein), loss of SLC26A3
mediated transport
Diarrhoea
Secretory (large volume,
NPO no effect)
Osmotic (low volume)
5. Pathophysiology cont…..
SLC26A3 gene (family of 26 member, >30 mutations) encodes for
a trans-membrane protein {apical epithelial (Cl⁄HCO3)
exchanger}
Result:
defective Gut absorption of Cl and secretion of HCO3
The coupled epithelial Na+⁄H+ transport through the
Na+⁄H+ exchangers (NHE2 and⁄ or NHE3) is defective
& leads to
intestinal loss of both NaCl, fluid
watery Cl rich diarrhoea.
6. At birth
Distended abdomen
Visible peristalsis
Most are LBW
d/d: intestinal obstruction
D1: Profuse watery diarrhea
?????urine, misdiagnosed as
delayed passage of meconium
7. CCD Vs GI obstruction
Family history (AR)
Local demographics
Normal peristalsis
ANSS:
Generalized dilatation of gut
with polyhydramnious
Increase chloride in AF
8. Diagnosis
Typical clinical picture:
Watery diarrhea since birth
Metabolic alkalosis
High fecal chloride >90 mmol/L
fecal pH between 4 and 6
Genetic testing for mutation
If excessive fluid loss and salt depletion*:
↓diarrhea & low faecal Cl of even 40 mmol/L
Repeat faecal samples for diagnosis
>3 months of life:
diagnosis by high fecal chloride concentration
9. In the 1st hour after birth
Dehydration, Hypochloremia, Hyponatremia,
Activate renin-angiotensin system
Hyperaldosteronism (compensatory mechanism) →K+ depletion and metabolic
alkalosis
Laboratory findings (untreated): hypochloraemia, hypokalemia and metabolic
alkalosis
11. Complications
Diarrhoea and fecal incontinence-
Life long
No of stools: 2-7L/day
Renal injury-
Major complication
Chronic hypovolemia →secondary effects
↑ renin, aldosterone with secondary hyperaldosteronism
Vascular changes –hypertensive changes (±BP)
Chronic K+ loss→ impaired function of renal tubular and
intestinal absorptive cells
12. Complications……..
Male subfertility –
low concentration of poorly motile spermatozoa
abnormal morphology +
high seminal chloride with low pH
large bilateral spermatoceles
Hyperuricaemia & gout –
age dependent increasing risk
Sweat gland-
increased chloride (similar to CF)
13. Management
Neonatal period: NaCl and KCl added to IV
maintenance fluids
120-300 mL/day (patients aged 0-7 days)
500-700 mL/day (patients aged more than
7days)
Bicarbonate free fluid
IV → PO: Q8/Q6 H
Salt substitution therapy (NaCl and KCl)
14. Salt replacement therapy
↑ intestinal absorption (mechanisms-not known)
Inhibits development of hypochloraemic and hypokalaemic metabolic
alkalosis
Despite t/t:
Diarrhoea is persistent (defective SLC26A3-mediated anion transport
remains in the intestine)
↑ age: ↓ in amount of stools & electrolytes, but continuous loss of Cl
Insufficient replacement: Cl-free urine*
Adequate salt replacement: excretion of Cl in urine, ± electrolyte and
acid base status
The rationale:
15.
16. Proton pump inhibitor (Omeprazole)
Inhibition of gastric chloride secretion
protect endogenous chloride stores
reduce the amount of chloride presented to the
intestine
↓ in volume and frequency of stools
Cessation of incontinence
17. Oral Butyrate
Short-chain FA
Easily administered
Prevent severe dehydration episodes
Stimulates intestinal water and ion absorption (activation of a
parallel Cl-/butyrate and Na+/H+ exchanger, inhibit both basal
and adenosine 3’,5’-cyclic monophosphate–stimulated Cl
secretion)
Trophic effects : mediated through circulatory, hormonal, and
neural mechanisms
18. Cholestyramine
Binds bile acids → reduces intestinal secretion
Moderate reduction in diarrhoea (for 2 to 4
weeks)
19. Outcome
From fatal → treatable disease
Prompt recognition and management of
electrolyte loss
↓Constant dehydration
↓Dys/Hypoelectrolytemia
↑growth and development
↓Renal involvement
↓Activation of renin aldosterone system