-Cause is often unclear-may be genetic, environmental or intrauterine factors, 75% have no identified cause. -2-4% are from known teratogens-cocaine, alcohol, lithium, fluconazole , thalidomide retinoic acid, CMV, mumps, rubella, moms with IDDM, lupus, phenylketonuria. -10% from chromosome abnormalities (Down syndrome, Turner, DiGeorge)

### Congenital heart disease

## Step1: Identify the Problem### The problem here is to identify the condition that is often unclear in its cause, may be due to genetic, environmental or intrauterine factors, and has a percentage of cases that are from known teratogens, chromosome abnormalities.## Step2: Analyze the Given Information### The given information states that 75% of the cases have no identified cause, 2-4% are from known teratogens such as cocaine, alcohol, lithium, fluconazole, thalidomide, retinoic acid, CMV, mumps, rubella, moms with IDDM, lupus, phenylketonuria, and 10% from chromosome abnormalities like Down syndrome, Turner, DiGeorge.## Step3: Connect the Information to the Correct Answer### The information provided corresponds to the characteristics of congenital heart disease. This disease often has an unclear cause, can be due to various factors including genetic, environmental or intrauterine factors, and has a percentage of cases that are from known teratogens and chromosome abnormalities.