Hepatic veno-occlusive disease with immunodeficiency (also called VODI) is a hereditary disorder of the liver and immune system. Its signs and symptoms appear after the first few months of life.

Hepatic veno-occlusive disease is a condition that blocks (occludes) small veins in the liver, disrupting blood flow in this organ. This condition can lead to enlargement of the liver (hepatomegaly), a buildup of scar tissue (hepatic fibrosis), and liver failure.

Children with VODI are prone to recurrent infections caused by certain bacteria, viruses, and fungi. The organisms that cause infection in people with this disorder are described as opportunistic because they ordinarily do not cause illness in healthy people. These infections are usually serious and may be life-threatening. In most people with VODI, infections occur before hepatic veno-occlusive disease becomes evident.

Many people with VODI live only into childhood, although some affected individuals have lived to early adulthood.

VODI results from mutations in the SP110 gene. This gene provides instructions for making a protein called SP110 nuclear body protein, which is involved in the normal function of the immune system. This protein likely helps regulate the activity of genes needed for the body's immune response to foreign invaders (such as viruses and bacteria).

Mutations in the SP110 gene prevent cells from making functional SP110 nuclear body protein, which impairs the immune system's ability to fight off infections. It is unclear how a lack of this protein affects blood flow in the liver.

Normal Function

The SP110 gene provides instructions for making a protein called SP110 nuclear body protein, which is a component of cellular structures called nuclear bodies. Nuclear bodies are located within the nuclei of cells, where they help control the activity of certain genes. Nuclear bodies are also involved in the regulation of cell division, the self-destruction of cells that are damaged or no longer needed (apoptosis), and the normal function of the immune system.

SP110 nuclear body protein is active primarily in immune system cells called leukocytes and in the spleen. It likely helps regulate the activity of genes needed for the body's immune response to foreign invaders (such as viruses and bacteria).

Health Conditions Related to Genetic Changes

Hepatic veno-occlusive disease with immunodeficiency

At least five mutations in the SP110 gene have been found to cause hepatic veno-occlusive disease with immunodeficiency (VODI). Each of these mutations leads to the production of a nonfunctional version of SP110 nuclear body protein. A lack of functional protein impairs the immune system's ability to fight off foreign invaders, allowing recurrent and persistent infections to develop. It is unclear how the loss of SP110 nuclear body protein disrupts blood flow in the liver, leading to enlargement of the liver (hepatomegaly), a buildup of scar tissue (hepatic fibrosis), and liver failure.

Other disorders

Several common variations (polymorphisms) in the SP110 gene have been studied as risk factors for lung (pulmonary) tuberculosis. This disease is a contagious bacterial infection. At least one study has found that certain variations in the SP110 gene may influence the risk of infection with the bacteria that cause pulmonary tuberculosis. However, several other studies have not found such an association. SP110 variations are probably not a major genetic risk factor for this disease.

Other Names for This Gene

• FLJ22835
• IFI41
• IFI75
• interferon-induced protein 41, 30kD
• interferon-induced protein 41/75
• interferon-induced protein 75, 52kD
• IPR1
• nuclear body protein SP110
• phosphoprotein 41
• phosphoprotein 75
• SP110_HUMAN
• speckeled, 110-KD
• transcriptional coactivator Sp110

Genomic Location

This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.

VODI appears to be a rare disorder; approximately 20 affected families have been reported worldwide. Most people diagnosed with the condition have been of Lebanese ancestry. However, the disorder has also been identified in several individuals with other backgrounds in the United States and Italy.