the Fragile X syndrome or Martin and Bell is a disease of congenital origin that produces retarded, being the second leading cause of mental retardation. The cause lies in the FMR1 gene, which is a mutation that inhibits the expression of this gene, turning it off.
people who suffer from this syndrome show a phenotype (i.e., an expression of the genetic defects) very characteristic:
* long face
* prominent front
* pronounced Chin
* Otoplasty
* large testes
these features add other pathologies as:
* mental retardation
* lax skin
* hyperactivity and attention problems
* flutter with arms
* limited eye contact
* joints hiperlaxas or hiperelásticas
transmission
to be a disease X-linked, men have a single pair always develop the disease, while women must possess this gene by double heading, which decreases the risk of this syndrome female, which usually tends to be the transmitter of disease. It is due to their genetic origin prenatal diagnosis is of great importance, namely the amniocentesis or even pre-implantacional diagnosis can prevent these mutations in the event that has previously been in a family or known carrier one of the people of the couple.
Tags: genetic diseases
