Carriers of the Sickle Cell Trait
Sickle cell trait (SCT) is a genetic condition where a person receives a copy of the sickle cell gene from one of their parents. Sickle cell disease (SCD) occurs when a person receives a copy of the sickle cell gene from both parents. People with SCD can have life-long complications because of the disease, such as extreme pain episodes, anemia (decreased amount of red blood cells), and jaundice (yellowing of the skin, eyes, and mouth). Those with SCT generally do not experience symptoms, and it is rare to develop complications.
In most individuals, red blood cells found in the body are round. Those diagnosed with SCD have red blood cells that are sickle (or crescent) shaped. Those with SCT have both round red blood cells and sickle shaped red blood cells.
Under conditions of extreme stress, such as dehydration or low oxygen levels during intense exercise, sickle shaped red blood cells can group or clump in areas of the body that have the least oxygen present. One area of the body is the medulla of the kidney, which is the innermost part of the kidney. Chronic low oxygen levels along with tissue damage from sickled cells in the kidney medulla increase the risk of developing a rare kidney cancer type called renal medullary carcinoma (RMC).
Risk Factors
Individuals with SCT who are diagnosed with RMC usually have a specific profile:
- Age: under the age of 30
- Sex: men are two times more likely than women
- Ethnicity: originate or have family members from Africa, South Asia, Southern Europe, Central and Southern America, or the Middle East (areas where malaria and SCT are common)*
- Activities: have a history of participating in intense exercise and sports
* SCT protects from malaria because the sickle shaped red blood cells make it harder for the malaria parasite to survive and grow. This is why SCT is more common in places with a lot of malaria.
Individuals who do not fit this profile can also be diagnosed with RMC, but it is very uncommon.
Additional risk factors that increase your chances of being diagnosed with kidney cancer include:
- Smoking
- Obesity
- High blood pressure
- Family history of kidney cancer
- Other genetic conditions
Signs and Symptoms
Most people diagnosed with kidney cancer have similar symptoms. These include:
- Blood in your urine
- Unexplained pain in your lower back or side
- A mass or lump in your lower back or side
- Fatigue
- Loss of appetite
- Unintentional weight loss
- Ongoing fevers without an infection
Each of these symptoms on their own does not mean you have kidney cancer. They may be a sign of other health issues. If you have any of these symptoms, talk to your healthcare team to see if you need further testing or treatments.
Take Action
Engage With Your Health
Know if you are a carrier of SCT. Blood testing can be used to determine if red blood cells contain abnormal hemoglobin, indicating the presence of SCT.
There are actions you can take that may help reduce your risk of getting kidney cancer. These include:
- If you smoke, quit. The CDC has resources to help.
- If you have high blood pressure or chronic kidney disease, make sure to follow your doctor’s recommendations on how to manage it.
- Maintain a healthy lifestyle by eating well, engaging in physical activities you enjoy, and reducing stress.
You can also support your health by staying engaged with your health care team. This includes:
- Help your doctor understand your unique risk for kidney cancer.
- Continue, or start, to get regular physicals from your doctor.
- Watch out for signs and symptoms of kidney cancer, and tell your care team if you have any.
Since high intensity exercise along with SCT is associated with the development of RMC, it is recommended to stay in the range of 50-70% of your maximum heart rate to prevent kidney damage. It is important to know your limits. Make sure to consult with healthcare providers to find the right intensity level of exercise for you. Consider guidelines from reputable organizations like the CDC, National Athletic Trainers’ Association (NATA), and National Collegiate Athletic Association (NCAA) for safe exercise practices if you are involved in athletic activities or rigorous professions.
Resources
The KCA has partnered with Chris “CJ” Johnson Foundation. Learn more about their resources here: Chris “CJ” Johnson Foundation
Other helpful resources:
References:
Information on this page last reviewed: January, 2025
The Populations at Higher Risk content is made possible with the generous support of
Keep Learning:
The Kidney Cancer Association provides educational literature for anyone impacted by kidney cancer.