Analysis of the Phenotypes in the Rett Networked Database

Table 2

Compliance of the RND data with the revised diagnostic criteria [11] for patients positive for a mutation in MECP2. Peripheral vasomotor disturbances are accounted for in the “small cold hands and feet” score. The item “diminished response to pain” is not present in RND data.

Clinical sign		+ (%)
A period of regression	743	715 (96.2)
Necessary criteria
Partial or complete loss of acquired purposeful hand skills	743	673 (86.5)
Stereotypic hand movements	880	599 (68.1)
Partial or complete loss of acquired spoken language	754	513 (68.0)
Gait abnormalities	821	365 (44.5)
Supportive criteria
Breathing disturbances when awake	824	441 (53.5)
Bruxism when awake	829	515 (62.1)
Impaired sleep pattern	926	419 (45.2)
Abnormal muscle tone	—	—
Peripheral vasomotor disturbances	—	—
Scoliosis or kyphosis	853	444 (52.1)
Growth retardation	771	419 (54.3)
Small cold hands and feet	160	81 (50.6)
Inappropriate laughing or screaming spells	560	171 (30.5)
Diminished response to pain	—	—
Eye pointing	958	843 (88.0)

represents the number of cases for which the corresponding item is present in the patient file; + represents the number of cases positive for the clinical signs, and the percentage is provided in brackets. Growth retardation was considered to be present when the weight was below the 25th percentile. When height is considered, 54.3% of MECP2-positive patients are below the 25th percentile.