Nephrogenic diabetes insipidus
Nephrogenic diabetes insipidus can be cuased by a mutation of Aquaporin 2 (AQ2). The mutations are K228E, V24A and R187C. These mutations could cause structural defects in the water channel affecting their permeablitity and functionality. These defects can cause the renal collecting duct not to respond to ADH and this releases excessive amounts of water in the urine. The urine should be concentrated, as ADH makes the urine more concentrated to maintain the water in your body therefore AQ2 will not reabsorb water from the kidney, resulting in abnormal water loss.
Sufferers may have insupressible thirst and will urinate a vast amount, usually more than 3 - 15 liters per day. Dehydration can occur if insufficent fluids are consumed. This can result in dry mucous membranes, dry skin, sunken appearance to eyes and sunken fontanelles (soft spot) in infants.
Other symptoms that can occur due to inadequate fluids include:
- Fatigue, lethargy
- Low body temperature
- Muscle pains
- Rapid heart rate
- Weight loss