Which are the symptoms of Schimke Immuno-Osseous Dysplasia?

Schimke Immuno-Osseous Dysplasia (SIOD) is a rare genetic disorder that affects multiple systems in the body. It is characterized by a combination of immune system dysfunction and skeletal abnormalities. SIOD is caused by mutations in the SMARCAL1 gene, which is responsible for producing a protein involved in DNA repair and gene regulation.

Immune System Symptoms:

• Recurrent infections: Individuals with SIOD often experience frequent and severe infections, particularly of the respiratory and urinary tracts. These infections can be bacterial, viral, or fungal in nature.


• Immunodeficiency: The immune system of individuals with SIOD is compromised, leading to a reduced ability to fight off infections. This can result in a higher susceptibility to opportunistic infections.


• Autoimmune disorders: SIOD patients may develop autoimmune conditions such as autoimmune hemolytic anemia, where the immune system mistakenly attacks red blood cells, or autoimmune thyroiditis, which affects the thyroid gland.

Skeletal Symptoms:

• Growth retardation: Children with SIOD typically have short stature and delayed growth. The growth retardation is often evident during early childhood.


• Skeletal abnormalities: SIOD is associated with various skeletal abnormalities, including a condition called spondyloepiphyseal dysplasia. This affects the growth and development of the spine and long bones, leading to short trunk and limbs.


• Osteoporosis: Individuals with SIOD may develop osteoporosis, a condition characterized by weak and brittle bones. This can increase the risk of fractures.


• Progressive renal disease: SIOD can also affect the kidneys, leading to progressive renal disease. This can result in impaired kidney function and eventually kidney failure.

Other Symptoms:

• Intellectual disability: Many individuals with SIOD have intellectual disability, ranging from mild to severe. This can affect cognitive abilities, learning, and overall development.


• Endocrine abnormalities: SIOD can cause various endocrine abnormalities, such as hypothyroidism (underactive thyroid), growth hormone deficiency, and early puberty.


• Eye abnormalities: Some individuals with SIOD may have eye abnormalities, including retinal degeneration, myopia (nearsightedness), and cataracts.


• Facial features: SIOD can be associated with distinct facial features, including a prominent forehead, a flattened bridge of the nose, and a small chin.

It is important to note that the severity and specific combination of symptoms can vary among individuals with SIOD. Some individuals may experience more severe immune system dysfunction, while others may have more pronounced skeletal abnormalities. Early diagnosis and management of SIOD are crucial to provide appropriate medical care and support for affected individuals.