Rett Syndrome is one of the rare neurodevelopmental disorders that is mostly found in females. In males, the syndrome is rare. The disorder leads to the loss of motor skills like speech. However, the symptoms of a Rett syndrome are visible after 6 to 18 months of age as babies tend to lose command over skills they have learned until this stage. Many babies who have learned how to crawl tend to forget it as well, which is usually the first sign that is present amongst babies from a very young age. Overall during the time of birth, the presence or chances of developing a Rett syndrome over the years might not be visible.
Development of Rett Syndrome in a male embryo
Rett Syndrome in males has very severe and deadly symptoms if developed. Most of the babies hardly survive if they are affected by this syndrome. It's assumed that most male embryo does not develop during the pregnancy due to the severe condition, and that is that the reason Rett syndrome is rare in boys.
Diagnosed males tend to have breathing and feeding difficulties, along with seizures due to which their chances of survival are low.
The MECP2 gene on the X Chromosome
The MECP2 gene is positioned on the X chromosome, one of the sex chromosomes. Females have two X chromosomes with no Y chromosome, and males only have one X chromosome and one Y chromosome. Since the MECP2 gene is found on the X chromosome, females have two copies of the MECP2 gene, while boys have only one copy.
Chromosome X inactivation
Another important term that is relevant to this explanation is the X inactivation. In fact, X inactivation is a process by which one of the copies of the X chromosome is inactivated. Almost all females have two X chromosomes, and the X-inactivation process prevents them from having a double amount of X chromosome gene products than males, who only own one copy of the X chromosome.
Since the MECP2 is on the X chromosome, and due to the X inactivation process, that result is that females randomly use theone of their X chromosome. Randomly they will use the X Chromosoe that has the MECP2 with a mutation that causes Rett Syndrome, or the X Chromosome with the proper MECP2 gene that does not have the mutation, which means some of their MECP2 work properly. Since males have only one copy of the X chromosome, they will have only the MECP2 mutation, which leads to much more severe problems and symptoms.
More Circumstances that can develop Rett Syndrome in Men
Some various factors and circumstances can lead to the development of Rett Syndrome in Men. Some of the common conditions that can be an underlying cause of this syndrome are as follows:
Klinefelter syndrome is a condition that can trigger the development of Rett Syndrome in men. It is a genetic condition under which males tend to have two X chromosomes along with their Y chromosome. However, such genetic condition is quite rare as only 1 out of 1000 males are diagnosed with it, and there is no such evidence that every individual who has two X chromosomes is going to suffer through a Rett Syndrome.
Another condition that can have a link with the development of a Rett syndrome is a condition called Mosaicism. In this condition, males tend to have two different populations of cells within their bodies. However, in some males, the cells have a healthier version of the gene. Whereas, in others, especially the ones with a Rett syndrome, the MECP2 had the mutation.
The level of MECP2 mutation is going to determine the severity of the syndrome. However, when a mutation occurs in males, the chances of them developing learning or behavioral difficulty increase. MECP2 mutation in males might not produce or lead to the symptoms related to the Rett syndrome symptoms that are present in females.
Furthermore, various researches are being carried out to determine how likely it is for males to be diagnosed with this syndrome. For instance, a new study has been revealed that males can be affected by this syndrome even if there is no history of the neurodevelopmental disorder in their family. Genetic disorder testing should be done in males as well in order to detect the syndrome at an early stage, especially amongst males who tend to develop serious neurological abnormalities. There are chances that medical intervention can help the baby to survive for a few years.