. 2019 Summer;13(3):25–34.

Table 1.

Diagnostic criteria for Rett syndrome (14)

Necessary criteria
(1)Apparently normal prenatal and perinatal period (2)Apparently normal psychomotor development through the first 6 months (3)Normal head circumference at birth (4)Deceleration of head growth between the ages of 5 months and 4 yr (5)Loss of acquired purposeful hand skills between the ages of 6 and 30 months, temporally associated with communication dysfunction and social withdrawal (6)Development of severely impaired expressive and receptive language, and presence of apparent severe psychomotor retardation. (7)Stereotypic hand movements such as hand wringing/squeezing, clapping/tapping, mouthing and washing/rubbing automatisms appearing after purposeful hand skills are lost (8)Appearance of gait apraxia and truncal apraxia/ataxia between ages 1 and 4 yr of age (9)Diagnosis tentative until 2-5 yr of age

Necessary criteria

(1)Apparently normal prenatal and perinatal period
(2)Apparently normal psychomotor development through the first 6 months
(3)Normal head circumference at birth
(4)Deceleration of head growth between the ages of 5 months and 4 yr
(5)Loss of acquired purposeful hand skills between the ages of 6 and 30 months, temporally associated with communication dysfunction and social withdrawal
(6)Development of severely impaired expressive and receptive language, and presence of apparent severe psychomotor retardation.
(7)Stereotypic hand movements such as hand wringing/squeezing, clapping/tapping, mouthing and washing/rubbing automatisms appearing after purposeful hand skills are lost
(8)Appearance of gait apraxia and truncal apraxia/ataxia between ages 1 and 4 yr of age
(9)Diagnosis tentative until 2-5 yr of age