Lifetime Risk

Lifetime Risk is the risk of developing a given medical condition sometime during one's life. Average lifetime risk is calculated for a population group (such as Caucasians of European ancestry); your own personal lifetime risk may be calculated by applying your odds/risk ratios (based on your genotypes, assuming high heritability for the condition in question) to the average for the population you belong to. Incidentally, average lifetime risk for a population should specify which birth year/cohorts it applies to.

Often, however, population statistics are a bit hard to come by, and furthermore, the more interesting "personal genomics" statistic might be residual lifetime risk in light of your own genome and your current age ... but there isn't enough medical and epidemiological data to actually calculate this yet for any complex disease, despite what the marketing departments of various genetic testing companies might imply.

For Caucasian populations, a sampling of average lifetime risk for various medical conditions listed in SNPedia follows:

Medical Condition	Average Lifetime Risk	Reference	Age-specific data
Age related macular degeneration	8%	[PMID 27125062]
Alzheimer's disease	19.5% women, 10.3% men	10.1016/j.jalz.2018.02.001
Asthma	13%
Atherosclerosis	45%	[PMID 16461820]
Atrial fibrillation	24%	[PMID 15313941]
Bladder cancer	2.4%	NIH/NCI
Breast cancer	8%		BC risk by age
Cancer (any invasive)	37% women, 45% men	[1]
Celiac disease	10%
Colorectal cancer	4.8%	NIH/NCI
Crohn's disease	0.5%
Death (any cause)	100%	[2][3]
Diabetes (Type-1 and -2)	35%	[PMID 14532317]
Endometrial cancer	2.7%	NIH/NCI
Exfoliation glaucoma	15%
Gallstone disease (symptomatic)	10%	[PMID 8363172]
Hypertension	20%
Leukemia	1.4%	NIH/NCI
Lung cancer	6.9%	NIH/NCI
Melanoma	2%	NIH/NCI
Multiple sclerosis	2.3%
Neuroblastoma	0.001%
Obesity	30%
Osteoporosis	15%
Ovarian cancer	1.3%	[4]
Pancreatic cancer	1.5%	NIH/NCI
Parkinson's disease	3.5%	[PMID 30279211 ]
Prostate cancer	15%	[5] NIH/NCI
Psoriasis	2-4%	[PMID 9470911]
Restless legs syndrome	10%
Rheumatoid arthritis	1%
Schizophrenia	1%	[PMID 10025441]
Stroke	19%	[PMID 30279211 ]
Testicular cancer	0.4%	[6]
Type-1 diabetes	0.4%
Type-2 diabetes	27%
Venous thromboembolism	8.1%	[PMID 26597668 ]

Additional sources with useful lifetime risk data include:

Cancer Risks - lifetime risk of developing or dying from various cancers based on US NCI/SEER 2012-2014 data, compiled by the American Cancer Society
Major risks - by age, gender and smoking status; however, data is from 2008 and has not been updated