Familial encephalopathy with neuroserpin inclusion bodies
Encyclopedia
Familial encephalopathy with neuroserpin inclusion bodies (FENIB) is a progressive disorder of the nervous system
that is characterized by a loss of intellectual functioning (dementia
) and seizures. At first, affected individuals may have difficulty sustaining attention and concentrating. Their judgment, insight, and memory become impaired as the condition progresses. Over time, they lose the ability to perform the activities of daily living, and most people with this condition eventually require comprehensive care.
The signs and symptoms of familial encephalopathy with neuroserpin inclusion bodies vary in their severity and age of onset. In severe cases, the condition causes seizures and episodes of sudden, involuntary muscle jerking or twitching (myoclonus) in addition to dementia. These signs can appear as early as a person's teens. Less severe cases are characterized by a progressive decline in intellectual functioning beginning in a person's forties or fifties.
Mutations in the SERPINI1 gene
cause familial encephalopathy with neuroserpin inclusion bodies. The SERPINI1 gene provides instructions for making a protein called neuroserpin. This protein is found in nerve cells, where it plays a role in the development and function of the nervous system. Neuroserpin helps control the growth
of nerve cells and their connections with one another, which suggests that this protein may be important for learning and memory. Mutations in the gene result in the production of an abnormally shaped, unstable version of neuroserpin. Abnormal neuroserpin proteins can attach to one another and form clumps (called neuroserpin inclusion bodies or Collins bodies) within nerve cells. These clumps disrupt the cells' normal functioning and ultimately lead to cell death. Progressive dementia results from this gradual loss of nerve cells in certain parts of the brain. Researchers believe that a buildup of related, potentially toxic substances in nerve cells may also contribute to the signs and symptoms of this condition.
This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. In many cases, an affected person has a parent with the condition.
Nervous system
The nervous system is an organ system containing a network of specialized cells called neurons that coordinate the actions of an animal and transmit signals between different parts of its body. In most animals the nervous system consists of two parts, central and peripheral. The central nervous...
that is characterized by a loss of intellectual functioning (dementia
Dementia
Dementia is a serious loss of cognitive ability in a previously unimpaired person, beyond what might be expected from normal aging...
) and seizures. At first, affected individuals may have difficulty sustaining attention and concentrating. Their judgment, insight, and memory become impaired as the condition progresses. Over time, they lose the ability to perform the activities of daily living, and most people with this condition eventually require comprehensive care.
The signs and symptoms of familial encephalopathy with neuroserpin inclusion bodies vary in their severity and age of onset. In severe cases, the condition causes seizures and episodes of sudden, involuntary muscle jerking or twitching (myoclonus) in addition to dementia. These signs can appear as early as a person's teens. Less severe cases are characterized by a progressive decline in intellectual functioning beginning in a person's forties or fifties.
Mutations in the SERPINI1 gene
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
cause familial encephalopathy with neuroserpin inclusion bodies. The SERPINI1 gene provides instructions for making a protein called neuroserpin. This protein is found in nerve cells, where it plays a role in the development and function of the nervous system. Neuroserpin helps control the growth
Cell growth
The term cell growth is used in the contexts of cell development and cell division . When used in the context of cell division, it refers to growth of cell populations, where one cell grows and divides to produce two "daughter cells"...
of nerve cells and their connections with one another, which suggests that this protein may be important for learning and memory. Mutations in the gene result in the production of an abnormally shaped, unstable version of neuroserpin. Abnormal neuroserpin proteins can attach to one another and form clumps (called neuroserpin inclusion bodies or Collins bodies) within nerve cells. These clumps disrupt the cells' normal functioning and ultimately lead to cell death. Progressive dementia results from this gradual loss of nerve cells in certain parts of the brain. Researchers believe that a buildup of related, potentially toxic substances in nerve cells may also contribute to the signs and symptoms of this condition.
This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. In many cases, an affected person has a parent with the condition.