What are the different types of mental retardation?

Mental retardation types usually fall into five categories caused by genetic mutations or abnormalities that develop before birth. They include cranial abnormalities, cretinism, phenylketonuria (PKU), Down syndrome and nesydromic mental retardation. All types of mental retardation usually cause mental delays measured by intelligence tests. People with mental retardation often also suffer from developmental delay, which affects their ability to perform basic life skills. Sometimes they are called mongoloids, children born with this defect usually develop a flat face and nose that seem too wide. The eyes are usually oblique and the tongue seems greater than normal. Other physical properties include short neck and hands with hard fingers. Small fingers on both hands can be curved.

There is no cure for Down syndrome, but timely intervention would come up with people with the condition of living more productive lives and cope with disabilities. Many patients with disorder liveE partially independent life as adults, with a life expectancy of up to 55 years. The only known risk associated for this genetic disorder is the mother's age when it becomes pregnant. Women over 45 years of age face a better chance of delivering a child with Down syndrome.

Some types of mental retardation stem from the size of the head at birth or shortly thereafter. Children born with macrocephalia usually develop unusually large heads and brains. Microcephalies means that the brain and head normally cannot grow and may be caused by infection or exposure to women of radiation during pregnancy. Children born with microcephaly usually develop cone -shaped heads, along with retreating foreheads and chin. Hydrocephaly describes a rare condition when too much cerebrospinal fluid accumulates.

Cretinism is one type of mental retardation associated with thyroid disorder. This could lead to a lack of endocrine if sufficient iodine do notwas absorbed by the fruit. Excessive bleeding at birth and some diseases can also lead to a cretinism, including measles, diphtheria and black cough.

PKu occurs in a child born without a critical enzyme that decomposes protein. Without this chemical, amino acid accumulates in the blood, which could lead to brain damage. Symptoms usually occur between six and 12 months after birth as mental retardation. Disorders stem from the recessive gene disorder inherited from both parents. The PKU test immediately after birth can identify a disorder that can be treated with a diet to reduce the severity of the brain damage.

Non -dromic mental retardation is the most common of all types of mental retardation. It occurs when the gene responsible for memory and learning does not normally work. There are no physical signs of this disorder that is not genetic. Mutation usually occurs in the baby's brain as it develops.