Longevity in Rett syndrome: analysis of the North American Database.
OBJECTIVE
To determine longevity in Rett syndrome (RTT) from a large cohort.


METHODS
The North American RTT Database allows the examination of longevity in a large cohort of individuals with RTT from the United States and Canada. This database contains information on 1928 individuals, 85.5% with typical RTT, 13.4% with atypical RTT, and 1.1% with a mutation in the methyl-CpG-binding protein 2 gene (MECP2) but not RTT. Kaplan-Meier analyses were performed to assess longevity.


RESULTS
Earlier decennial cohorts exhibited better survival than recent cohorts, with most participants surviving into middle age. Comparing overall survival in persons with typical RTT and atypical RTT revealed greater mortality in typical RTT across the observed lifespan (P < .0001). Comparing survival in persons with RTT and identified MECP2 mutations and persons with unknown MECP2 status demonstrated greater mortality in the latter group (P < .0001, log-rank test).


CONCLUSIONS
This analysis provides strong evidence for significant longevity in RTT and indicates the need for careful planning for long-term care of these women. The disproportionately greater survival seen in earlier time periods and in persons with atypical RTT may be attributed to more severely affected individuals dying before diagnosis in the former and to greater numbers with milder variants (ie, preserved speech and delayed onset) in the latter.
Kirby
Russell S
RS
School of Public Health, University of Alabama at Birmingham, Birmingham, AL, USA..
Lane
Jane B
JB
Childers
Jerry
J
Skinner
Steve A
SA
Annese
Fran
F
Barrish
Judy O
JO
Glaze
Daniel G
DG
Macleod
Patrick
P
Percy
Alan K
AK
D006801:Humans; D053208:Kaplan-Meier Estimate; D051783:Methyl-CpG-Binding Protein 2 / Q000235:genetics; D009026:Mortality / Q000639:trends; D009656:North America / Q000453:epidemiology; D015518:Rett Syndrome / Q000235:genetics / Q000401:mortality*
C497392:MECP2 protein, human; D051783:Methyl-CpG-Binding Protein 2