IGHMBP2

The IGHMBP2 gene provides instructions for making an enzyme known as a helicase. Helicases attach to particular regions of DNA and temporarily unwind the two spiral strands of these molecules. When a cell prepares to divide to form two cells, the chromosomes are duplicated (replicated) so that each new cell will get a complete set of chromosomes. The replication process involves unwinding the DNA so that it can be copied. This mechanism is also involved in the production of RNA, a chemical cousin of DNA. The IGHMBP2 protein is also thought to be involved in the production of proteins from RNA (translation of DNA's genetic information). The IGHMPB2 protein is found in cells throughout the body.

spinal muscular atrophy - caused by mutations in the IGHMBP2 gene

More than 60 mutations in the IGHMBP2 gene have been found to cause a form of spinal muscular atrophy called distal spinal muscular atrophy type 1. Most of these mutations change single protein building blocks (amino acids) in the IGHMBP2 protein. IGHMBP2 gene mutations that cause distal spinal muscular atrophy type 1 disrupt the protein's ability to unwind DNA and RNA. The loss of this helicase function impedes DNA replication and RNA and protein production. Specialized nerve cells called alpha-motor neurons are particularly sensitive to a disruption in IGHMBP2 function. These neurons are located in the upper part of the spinal cord and the part of the brain that is connected to the spinal cord (the brainstem). Over time, a loss of IGHMBP2 function damages alpha-motor neurons and causes them to die, which leads to the progressive muscle weakness seen in people with distal spinal muscular atrophy type 1.