Jain et al developed a model for predicting the onset of seizures in a patient with Rett syndrome. The authors are from the University of Western Australia, the University of Sydney, Princess Margaret Hospital for Children and Children's Hospital at Westmead in Australia.
Seizures are relatively common in patients with Rett syndrome and may be refractory to treatment. Onset is usually between birth and 10 years of age, after which it levels off.
Risk factors for seizures:
(1) never walking
(2) abnormal development during the first 10 months of life
(3) type of mutation in the MECP2 gene
Parameters:
(1) age at diagnosis in months
(2) walking status
(3) mutation in the MECP2 gene (methyl-CpG binding protein 2)
(4) interval in months from the time of diagnosis
|
Parameter |
Finding |
Points |
|
walking status |
ever walked |
0 |
|
|
never walked |
-1.0652 |
|
mutation in the MECP2 gene |
p.R168X |
-0.2362 |
|
|
p.T158M |
-0.1623 |
|
|
p.R294X |
-1.2261 |
|
|
p.R270X |
0.1696 |
|
|
p.R255X |
1.3107 |
|
|
p.R133C |
-1.4781 |
|
|
p.R306C |
1.0681 |
|
|
p.R106W |
-0.2141 |
|
|
C terminal |
-0.5268 |
|
|
early truncation |
0.1644 |
|
|
large deletions |
-0.1359 |
|
|
other |
-1.5216 |
|
|
none |
0 |
X =
= (0.0097 * (age in months at diagnosis))) + (points for walking) + (points for mutation) + 4.6135
Y =
= (-1) * (p value for shape) * X
= EXP((-1) * 1.0423 * X)
probability of being seizure free for a given period in months =
= EXP((-1) * Y * ((interval in months)^(p value for shape))) =
= EXP((-1) * Y * ((interval in months)^(1.0423)))
probability of seizure onset during the interval =
= 1 - (probability seizure free)
Specialty: Genetics
