Loss of eye contact and a lack of interest in play or games may also occur. Slow head growth can result in acquired microcephaly, a condition characterized by head circumference that is smaller than would normally be expected for age and gender.īetween 6 and 18 months of age, affected girls may enter a period of developmental stagnation. Head growth can slow down as early as 3 months of age. Low muscle tone (hypotonia) is also common before 6 months of age. However, researchers have noted that affected infants are often described as being very placid and having a poor sucking ability and a weak cry. Affected individuals should talk to their physician and medical team about their specific case, associated symptoms and overall prognosis.Īffected infants are generally described as having normal development until approximately 6 to 18 months of age. It is important to note that affected individuals may not have all of the symptoms discussed below.
A wide range of disability can potentially be associated with Rett syndrome. The disorder primarily affects females and most likely represents a spectrum of disease associated with mutations of the MECP2 gene. The symptoms, progression, and severity of Rett syndrome can vary dramatically from one person to another. This disorder is caused by duplicated material involving the MECP2 gene on the X chromosome. Another disorder, MECP2 duplication syndrome, has recently been described in the medical literature. This spectrum, sometimes referred to as MECP2-related disorders, includes classic Rett syndrome, variant Rett syndrome, MECP2-related severe neonatal encephalopathy, and PPM-X syndrome. Many researchers now consider Rett syndrome as part of a spectrum of disease relating to mutations of the MECP2 gene. Rett syndrome was first described in the medical literature by an Austrian physician named Andreas Rett in 1960s. Therefore, two girls of the same age with the same mutation can appear significantly different. The course and severity of Rett syndrome is determined by the location, type and severity of the MECP2 mutation and the process of random X-inactivation (see Causes section below). Most Rett syndrome cases are caused by identifiable mutations of the MECP2 gene on the X chromosome and can present with a wide range of disability ranging from mild to severe. Some children also have slowing of head growth (acquired microcephaly), Affected children often develop autistic-like behaviors, breathing irregularities, feeding and swallowing difficulties, growth retardation, and seizures. Additional abnormalities occur including impaired control of voluntary movements (ataxia) and the development of distinctive, uncontrolled hand movements such as hand clapping or rubbing. At this point, they lose previously acquired skills (developmental regression) such as purposeful hand movements and the ability to communicate. Infants with Rett syndrome generally develop normally for about 7 to 18 months after birth.
Rett syndrome is a progressive neurodevelopmental disorder that almost exclusively affects females.