Common genetic and familial diseases:

Alcoholism
Asthma
Diabetes
Epilepsy
Liver disease
Multiple Sclerosis
Obesity
Tay-Sachs disease
Allergies
Congenital abnormalities
Down’s Syndrome
Hearing disorders
Migraine headaches
Muscular Dystrophy
Phenylketonuria (PKU)
Thyroid disorders
Arthritis
Cystic Fibrosis
Dwarfism
Huntington’s Disease
Miscarriage
Myasthenia Gravis
Rh Disease

In particular, look for:

Blood disease—hemophilia, sickle cell trait, thalassemia

Cancer—breast, bowel, colon, ovary, skin, and stomach; leukemia

Cardiovascular disease or disorders—high blood pressure, atherosclerosis, heart attack, hyperlipidemia, stroke, congenital heart defects

Mental illness—manic-depressive disorders, schizophrenia, suicide

Respiratory disease—particularly emphysema, bacterial pneumonia, tuberculosis

Skin disorders—psoriases

Sudden Infant Death Syndrome (SIDS)

Systemic Lupus Erythematosus

Visual disorders—cataracts, dyslexia, glaucoma, and retinitis pigmentosa