What are kidney diseases?
Some kidney diseases can be due to genetic causes. Depending on the type of kidney disease and specific risks factors, the likelihood of genetic causes in a kidney patient can range from 10-70%. Glomerular diseases are a group of kidney conditions which can have genetic causes.
What are glomerular diseases?
Glomerular disease affects the kidney glomeruli, which are the kidney filtering units. There are about 1 million filtering units in each kidney. The glomeruli filter waste products and excessive water from blood so that they are passed out into the urine. Normal glomeruli are intact filters that will prevent red blood cells and protein in the blood from passing through into the urine.
In glomerular diseases, these glomeruli (filters) are damaged. As a result, red blood cells and protein pass through the leaky filters and enter the urine in excessive amounts. Excessive protein in the urine in turn further damages the kidney, resulting in a vicious cycle.
Glomerular diseases can occur due to many causes, such as:
- Infections, e.g. hepatitis B, hepatitis C, HIV virus
- Autoimmune conditions, e.g. Lupus, immunoglobulin A (IgA) nephropathy
- Genetic diseases e.g. Alport syndrome
- Other diseases, e.g. diabetes, high blood pressure
When doctors suspect glomerular disease, they will perform urine and blood tests to determine the cause. A kidney biopsy may also be performed. With kidney biopsy, different types of glomerular diseases can be classified, such as focal segmental glomerulosclerosis (FSGS) or minimal change disease.
A genetic cause is often suspected if
- There are other concurrent medical conditions that may be related to a genetic disease (e.g. hearing loss, specific eye conditions) in the patient and/or family member(s).
- There are family members with related kidney disease.
- The kidney biopsy shows features that may suggest a genetic cause.
- There is suboptimal or no response to the immunosuppressive drugs normally used to treat glomerular diseases.
Types of common genetic glomerular diseases
To date, there are nearly 100 genes known to cause genetic glomerular diseases.
The common conditions are described here: