Table 1 Definitions for estimating the probability of genetic susceptibility – P(G)
From: The nature of genetic susceptibility to multiple sclerosis: constraining the possibilities
Assume a population (P) of (n) individuals: (i = 1,2,…,n) | ||
|---|---|---|
P(MS) | = | The life-time probability of developing multiple sclerosis (MS) in the population |
(G i ) | = | Genotype of the (ith) individual in the population |
P(MS│G i ) = z i | = | Expected life-time probability of MS in the (ith) individual (genotype) |
(G−) | = | The subset of “non-susceptible” individuals for whom: P(MS│G i ) = 0 |
(G min ) | = | The subset of “minimally susceptible” individuals for whom: 0 < P(MS│G i ) < P(MS) |
(G) | = | The subset of “genetically susceptible” individuals for whom: P(MS│G i ) ≥ P(MS) |
(G T –) | = | the combined subset: (G min ) ∪ (G–) |
(G T ) | = | the combined subset: (G min ) ∪ (G) |
Z, X, Y, W,V | = | sets of: {z i }; in the entire population (Z); in the (G) subset (X); in the (G−) subset (Y), in the (G T ) subset (W), and in the (G T –) subset (V) |
P(MS│G−), P(MS│G min ), P(MS│G), | = | Expected life-time probability of MS for individuals in the subsets (G−), (G min ), or (G). By definition: P(MS│G) > P(MS│G min ) > P(MS│G−) = 0 |
p, q | = | p = P(G); q = P(G│MS) = P(G│IG MS ) |
x, x’, x i | = | x = P(MS│G); x’ = P(MS│G, IG MS ); x i = P(MS│G i ) given z i ε X |
y, y’ | = | y = P(MS│G min ); y’ = P(MS│G min , IG MS ) |
r | = | The largest value of P(MS│G i ) in the population |
P(MS│MZ MS ) | = | The conditional life-time probability of an individual developing MS, given that their monozygotic (MZ)-twin either has or will develop MS. This is equal to the proband-wise concordance rate for MZ twins. |
P(MS│DZ MS ), P(MS│S MS ) | = | The equivalent definition as for P(MS│MZ MS ) except for the individual having either a dizygotic (DZ) twin or sibling (S) with MS |
P(MS│IG MS ) = b | = | P(MS│MZ MS ) adjusted for the impact of an identical genotype (IG) sharing the same childhood and intrauterine micro-environments |