Trisomy 18p is a rare chromosomal disorder caused by the presence of an extra copy of genetic material on the short arm (p) of chromosome 18. It is a form of trisomy 18, a genetic disorder caused by the presence of three copies of chromosome 18 instead of the normal two copies. People with trisomy 18p typically have milder symptoms than those with other forms of trisomy 18. Common features include intellectual disability, developmental delays, and physical abnormalities.

The symptoms of Trisomy 18p vary from person to person, but some of the most common include:

- Low birth weight
- Small head size
- Abnormal facial features
- Heart defects
- Kidney and urinary tract abnormalities
- Gastrointestinal problems
- Poor muscle tone
- Seizures
- Developmental delays
- Intellectual disability

Trisomy 18p is caused by an extra copy of chromosome 18 in some or all of the cells of the body. This extra copy is usually inherited from a parent, but can also occur as a random event during the formation of reproductive cells (eggs and sperm).

Treatment for Trisomy 18p is supportive and depends on the individual's needs. Treatment may include physical therapy, occupational therapy, speech therapy, nutritional support, and medications to help manage symptoms. Surgery may be necessary to correct certain physical abnormalities. In some cases, palliative care may be recommended to help manage symptoms and improve quality of life.

The risk factors for Trisomy 18p include:

1. Advanced maternal age: Women over the age of 35 are more likely to have a baby with Trisomy 18p.

2. Family history: If a family member has had a baby with Trisomy 18p, the risk of having a baby with the condition increases.

3. Chromosomal abnormalities: Certain chromosomal abnormalities, such as translocations, can increase the risk of having a baby with Trisomy 18p.

4. Maternal health conditions: Certain maternal health conditions, such as diabetes, can increase the risk of having a baby with Trisomy 18p.

There is no cure for Trisomy 18p, but there are medications that can help manage some of the symptoms. These medications can include anticonvulsants to help control seizures, diuretics to help reduce fluid buildup, and medications to help with breathing difficulties. Additionally, physical and occupational therapy can help improve motor skills and muscle strength.