What Are the Different Types of Mental Retardation Syndromes?

Strictly speaking, the fragile X mental retardation syndrome is a single gene disease with X-linked dominant inheritance. A fragile site refers to a non-colored area of varying widths that appears at a constant part of a chromosome under certain culture conditions, forming cracks or shrinkage. In 1943, Martin and Bell described an X-linked mental retardation family: In 1969, Lubs first reported the "marker X chromosome" associated with mental retardation. Therefore, the fragile x mental retardation syndrome is often referred to as Martin-Bell synthesis Sign. ^[1]