From 'Trait' to 'Disease': Understanding the Sickle Cell Spectrum

It's a common misconception that sickle cell is a single condition. In reality, it exists on a spectrum, primarily determined by the specific genes a person inherits.

The main difference lies in whether someone has the sickle cell trait or a form of sickle cell disease.

What is Sickle Cell Trait (SCT)?

Think of sickle cell trait not as a disease, but as a genetic instruction manual that a person can carry but not necessarily experience. 

• How it works. Individuals with the trait (genotype AS) produce both normal hemoglobin (A) and sickle hemoglobin (S). There's always more normal hemoglobin (A) than sickle (S), which keeps the red blood cells healthy and flexible under most circumstances.
• Key takeaway. It is paramount to state clearly: Sickle cell trait is not a disease. The vast majority of the millions of people with SCT are healthy, lead completely normal lives, and are often unaware they carry the trait unless they undergo specific genetic testing.

However, they can pass the sickle gene on to their children, which is why awareness is so important for family planning.

While typically benign, it is also important to be aware that in very rare and specific extreme conditions — such as severe dehydration, intense physical exertion at high altitudes, or extreme low oxygen — some individuals with sickle cell trait may experience medical complications. These are not common, but they underscore why understanding one's genetic makeup is a key part of holistic health management.

Types of Sickle Cell Disease

Sickle cell disease (SCD) occurs when a person inherits two abnormal hemoglobin genes—one from each parent. The type of disease is defined by which two genes are inherited. These variations can influence the severity of symptoms.

• Sickle Cell Anemia (SS) — The most common and often most severe form. Caused by inheriting two sickle genes (S).
• Sickle Hemoglobin-C Disease (SC) — A common form where one sickle gene (S) is inherited with a different abnormal gene (C). Symptoms can be similar to SS but are sometimes milder.
• Sickle Beta-Thalassemia — Caused by inheriting one sickle gene (S) and one gene for beta-thalassemia (a different blood disorder).
• Sickle Beta-Plus Thalassemia (Sβ+) — Some normal hemoglobin is produced. Symptoms are often moderate.
• Sickle Beta-Zero Thalassemia (Sβ⁰) — No normal hemoglobin is produced. Symptoms are more severe, similar to SS.
• Other, Rarer Types (SD, SE) — These involve one sickle gene (S) and another rare abnormal hemoglobin gene (D, E, etc.). Their effects can vary.

While all forms of sickle cell disease share similar challenges, the specific genotype (like SS, SC, etc.) helps doctors understand what to expect and create a personalized care plan.

For more information on the Beaufort Memorial Sickle Cell Clinic or to make an appointment, call 843-522-5351.