Factors Responsible for Kidney Disease or Failure
We know there are various types of risk factors which can make kidneys sick, and stop its function completely. Kidney function loss can be slow or sudden depending upon the underlying core reason for the illness. On the basis of the primary reason responsible, we can broadly segregate the risk factors or causes for kidney disease/failure into three sections 1) Congenital Factors 2) Primary Factors, and 3) Secondary Factors. In this post, we will understand the hereditary causes which may be the grounds of many kidney diseases and End Stage Renal Disease (Kidney Failure) in the later phase in a person’s life.
1. Congenital or Hereditary Factors
‘Congenital’ word denotes to a biological condition(s) present in a person from birth. When used in medical reference, this term indicates about a disease or physical abnormality due to genetic disorder or caused by the environment. Hereditary malfunctioning of kidney can be categorised in two key points as below:
(a) Congenital Kidney Formation Defects (b) Congenital Kidney Functional Diseases
(a) Congenital Kidney Formation Defects
Imperfection in kidney’s shape, size, position or number which exists from the time of baby’s birth comes under this category. These congenital structural defects develop at the time when a baby is in the mother’s womb. Malfunctioning of a kidney can be due to any of these defects. Some of the flaws that affect kidneys’ normal function include renal agenesis, renal dysplasia and ectopic kidney etc.
Fusion Kidney Defects (Horseshoe Kidney)
Kidney is an organ, which is a pair, separated by each other and each one looks like a ‘bean.’ But sometimes a child may be born with joint kidneys where both kidneys are combined. Due to its unusual shape similar with a horse’s foot, it is commonly called as ‘horseshoe kidney’ but this is also known as renal fusion or super kidney. This is a hereditary disorder and found in one person out of 600 (mainly in men).
Ectopic kidney is a congenital defect in the organ related to placement of kidney. When kidney placement is not appropriate as per the usual norm, and is located above or below, it is called ectopic kidney. Unless there is a threat of blockage in urinary tract or kidney damage due to abnormal location, there is no need for treatment. However surgery may be required in case of obstruction and organ damage.
Renal (Kidney) Agenesis
This is the congenital kidney formation defect in which a child is born with either one kidney or probably both kidneys are missing. Both these conditions are called (i) Unilateral Renal Agenesis (URA) which refers to the absence of one kidney and (ii) Bilateral Renal Agenesis (BRA) when both kidneys are absent.
Renal (Kidney) Dysplasia
Renal (Kidney) dysplasia is a form of kidney deformity in which the kidney(s) are present but their development is abnormal and incomplete. In this condition the internal structure of one or both of a baby's kidneys do not develop normally while in the womb.
Abnormalities of the Ureters
The ureters are tubes that carry urine from the kidneys to the bladder. Though we are mentioning here about inherited kidney defects, taking note of ureter’s structural abnormalities is also essential as these tubes (ureters) are attached with kidney and affects kidney performance also. Therefore an abnormal size, shape, position and number of ureter tubes should be examined for any renal disease.
Conclusion on Congenital (Hereditary) Kidney Defects
Mostly, the defect is not known unless there is a symptom of low kidney function and tests are done. Usually, people with the kidney structural defect do not require any treatment/surgery to separate kidneys for shape correction, change location etc. as long as it is working fine. However if the defect is known and kidney disease run in the family history; it is suggested to check kidneys performance on a regular basis as the chances of developing complications are higher with ageing. In general, children with these conditions lead full, healthy lives although some children with renal agenesis or renal dysplasia are at greater risk for developing kidney disease.
(b) Congenital Kidney Functional Diseases
Congenital or Hereditary kidney diseases are illnesses passed from one or both the parents to the child through the genes. Sometimes a child can have malfunctioning of kidneys right from the time of birth which is referred as congenital kidney disease else the signs appear after some time of baby’s birth. There are many hereditary conditions where kidney has a tendency to make cysts leading to several diseases and ultimately organ failure.
Autosomal Polycystic Kidney Disease (APKD)
The most common inherited cystic kidney disease is APKD wherein several fluid-filled cysts build up in the kidneys which can be diagnosed before or after the birth of a child. These cysts multiply and grow big with time and destroy normal functional kidney tissues. Polycystic Kidney Disease (PKD) is a common genetic abnormality that cannot be cured and can be only treated to slow down the progression of kidney disease and also manage complications occurred due to PKD.
There are two different types of Polycystic Kidney Disease (PKD), dominant and recessive.
- Dominant PKD is most common and it occurs in 90% of cases and usually affects adults.
- Recessive PKD occurs in 10% of cases and usually affects children. ARPKD is a very uncommon disease. The baby with this condition has many small cysts all throughout the kidneys right from the time that they form in uterus.
Multicystic Kidney Disease (MKD)
This is when big cysts grow in a kidney that hasn't developed properly, ultimately causing it to stop functioning. While PKD always affects both kidneys, MKD usually affects just one kidney. Fortunately, the unaffected kidney takes over and most people with MKD lead a normal life with proper kidney function. MKD can be diagnosed by prenatal ultrasound before birth. It is very rare when surgical removal of the kidney is required.
This disease is a hereditary rare disorder which is found in 1 child out of 50,000 and has no cure. Alport Syndrome is caused by an abnormal gene (type of protein called collagen) that makes up the glomeruli. This condition begins to damage kidneys. Hearing loss and eye abnormalities are also seen together with kidney disease. People with Alport syndrome experience progressive loss of kidney function. Almost all affected individuals have blood in their urine (hematuria), which indicates abnormal functioning of the kidneys.
It is rare body disorder of glycoxylate metabolism in which oxalate is produced in excess and is the primary reason for kidney (renal) stones, recurrent nephrolithiasis and nephrocalcinosis to end-stage renal disease and systemic oxalosis. Since it is a hereditary health issue, the symptoms may originate right from the time of baby’s birth or may show up later in adulthood. Primary hyperoxaluria has three types which is categorised as type 1, type 2 and type 3.
Cystinuria is an inherited autosomal recessive disease which is a type of aminoaciduria. If a person has genetic disorder for developing cystinuria disease, there will be higher chances of amino acid cystein stone formation in the urine and will this will adversely affect kidneys, ureter and bladder.