Various factors, including kidney defects, can interfere with intrauterine development and cause changes in other body systems.
In this article we will talk about the causes, symptoms and types of Potter syndrome, Name by which this phenomenon is known, often of genetic origin.
What is the Potter sequence?
The terms “Potter sequence” and “Potter syndrome” they are used to refer to a set of physical malformations that occur in infants as a result of kidney damage, lack of amniotic fluid (oligohydramnios) or compression during intrauterine development.
In 1946, Dr Edith Potter described twenty cases of people without kidneys who presented more special physical features on the head and lungs. Potter’s contributions were essential in raising awareness of this disease, which is more common than previously thought.
Potter believed that this type of physical defect was always due to lack of kidneys or kidney agenesis; however, it was later discovered that there were other possible causes. The typological classification that we use today was developed around these and the associated alterations.
Causes of this alteration
Often Potter’s syndrome is associated with diseases and problems of the urinary system such as agenesis of the kidneys and ureter, polycystosis and multichystosis of the kidneys or obstruction of the urinary tract, which can be due to both genetic and environmental causes.
Many cases of Potter syndrome have a genetic origin (but not always hereditary); mutations have been identified on chromosomes 1, 2, 5 and 21 in variants with bilateral renal agenesis, and causes similar to other types have also been identified.
The development of the classical variant consists of a series of interrelated events; this is why it is also called the “Potter sequence”. Incomplete kidney and / or ureter formation or rupture of the amniotic sac they cause the fetus to not have enough amniotic fluid to form properly.
Main symptoms and signs
Sometimes the signs that characterize Potter’s syndrome can be observed already during intrauterine development. The most common is that medical tests show the presence of cysts in the kidneys or oligohydramnios or absence of amniotic fluid, Which is usually due to the rupture of the bag that contains it.
After birth, the facial features described by Potter become evident: flattened nose, epicánticos folds in the eyes, retracted chin and abnormally low ears. In addition, alterations can occur in the lower and upper limbs. However, these characteristics are not always present to the same degree.
Potter syndrome is also associated with malformations of the eyes, lungs, cardiovascular system, In the intestines and bones, especially in the vertebrae. The urogenital system is usually considerably impaired.
Types of Potter syndrome
At present, the different forms adopted by Potter syndrome are classified into five broad categories or types. These differ in both the causes and the clinical manifestations of nuclear. On the other hand, it is important to also mention the classic form of this disease and that associated with multicystic renal dysplasia, which was discovered very recently.
1. Type I
This variant of Potter syndrome occurs as consequence of autosomal recessive polycystic kidney disease, Hereditary disease that affects the kidneys and is characterized by the appearance of numerous cysts of small size and full of fluid. This causes the kidneys to increase in size and interferes with urine production.
2. Type II
The main feature of type II is renal agenesis or aplasia, that is, congenital absence of one or both kidneys; in the second case we speak of bilateral renal agenesis. Since other parts of the urinary system, such as the ureter, are also often affected, these signs are often referred to as “urogenital agenesis”. The origin is usually hereditary.
3. Type III
In this case, the malformations are due to an autosomal dominant polycystic kidney disease (unlike type I, in which the disease is transmitted by recessive inheritance). Cysts are observed in the kidneys and an enlargement of their size, as well as an increase in the frequency of vascular diseases. Symptoms usually appear in adulthood.
4. Type IV
Potter syndrome type IV is diagnosed when cysts appear and / or water (hydronephrosis) collects in the kidneys due to chronic obstruction of this organ or the ureter. This is a common variant during the fetal period that usually does not cause a miscarriage. The cause of these alterations can be both genetic and environmental..
5. Classic shape
When we talk about classic Potter syndrome, we are referring to cases where the kidneys are not growing (bilateral renal agenesis), just like the ureter. It has been proposed that the classic form described by Potter in 1946 could be considered an extreme version of Type II, also characterized by renal agenesis.
6. Multicystic renal dysplasia
Multicystic renal dysplasia is an impairment characterized by the presence of numerous and irregular cysts in the kidneys; compared to the term “polycystic”, “multiquistic” indicates a lower severity. Cases of Potter syndrome have been identified in recent years due to the disorder which could indicate a possible new type.