SNP Shot: Genomic Insights

Systemic lupus erythematosus (SLE) is a long-lasting (chronic) illness that causes inflammation in connective tissues. These tissues, like cartilage and blood vessel linings, provide strength and flexibility to the body. SLE affects people differently, with signs and symptoms varying widely. It can impact many parts of the body, including the skin, joints, kidneys, lungs, brain and spinal cord (central nervous system), and the blood-forming system. SLE belongs to a larger group of autoimmune diseases where the body's immune system mistakenly attacks its own healthy tissues and organs.

The initial signs of SLE can include extreme tiredness (fatigue), a general feeling of being unwell (malaise), fever, loss of appetite, and weight loss. Most people with SLE also experience joint pain, usually affecting the same joints on both sides of the body, as well as muscle pain and weakness. Skin problems are frequent. A distinctive symptom is a flat, red rash across the cheeks and nose, known as a "butterfly rash" due to its shape. This rash, which typically doesn't hurt or itch, often appears or worsens with sun exposure. Other skin issues in SLE can include calcium deposits under the skin (calcinosis), damaged blood vessels in the skin (vasculitis), and tiny red spots called petechiae. Petechiae are caused by a low number of blood clotting cells (platelets), resulting in bleeding under the skin. Hair loss (alopecia) and open sores (ulcerations) in the mouth, nose, or, less often, the genitals can also occur.

About one-third of individuals with SLE develop kidney disease (nephritis). Heart problems are also possible, such as inflammation of the heart's outer lining (pericarditis) and problems with the heart valves that control blood flow. Hardening and narrowing of the arteries due to plaque buildup (atherosclerosis), a common heart condition, is even more prevalent in people with SLE. Inflammation from SLE can also harm the nervous system, leading to symptoms like abnormal sensations and weakness in the limbs (peripheral neuropathy), seizures, stroke, and difficulties with thinking, learning, and remembering (cognitive impairment). Anxiety and depression are also common in SLE patients.

SLE is characterized by periods of worsening symptoms (exacerbations) and periods of improvement (remissions). Over time, SLE generally progresses, and damage to major organs can be life-threatening.

Inheritance:

SLE and other autoimmune conditions tend to occur more often in families, but the specific inheritance patterns are usually unknown. Individuals may inherit genes that increase or decrease their susceptibility to SLE, but most do not directly inherit the disease itself. While some SLE patients may have a gene that increases risk, not everyone with such a gene will develop the condition. A rare, inherited form of SLE follows an autosomal recessive pattern, meaning both copies of the responsible gene must have disease-causing changes. In this case, each parent carries one copy of the altered gene, but they typically don't exhibit signs or symptoms of the condition themselves.