Table 1.

Relationship of clinical variables to functional classification of p53 germline alleles based on the mean transactivation activity. For each allele, transactivation was determined quantitatively (luciferase-based) in 4 different reporter strains. Alleles were classified as Severe Deficiency (SD) or Partial Deficiency (PD) alleles if their mean residual activity was <25% or ≥25% of that of the WT allele (100% activity), respectively. A separate group of 52 alleles were classified as Obligate Severe Deficiency (O-SD) alleles in terms of transactivation, by virtue of nonsense mutations, frameshifts or other mutations that give rise to a truncated protein. The p values are for testing whether the proportion of families exhibiting a given clinical characteristic differed according to the type of allele carried by the family.

	SD	PD	O-SD	SD vs PD (p value)	SD vs O-SD (p value)	PD vs O-SD (p value)
Number of alleles	69	34	52
Class distribution of families
NA	7 (4%)	5 (11%)	2 (3%)	ns	ns	ns
noFH	25 (15%)	6 (14%)	5 (7%)	ns	ns	ns
FH	24 (14%)	15 (34%)	6 (9%)	0.004	ns	0.001
LFL	45 (26%)	13 (30%)	24 (34%)	ns	ns	ns
LFS	70 (41%)	5 (11%)	33 (47%)	0.0002	ns	0.0001
Total	171 (100%)	44 (100%)	70 (100%)
Families with individuals with multiple tumors	107 (63%)	17 (39%)	40 (57%)	0.006	ns	ns