Alexis Villa of California, born in 1995, has type 3 SMA. She uses leg braces most of the time, and occasionally a wheelchair for longer distances. She loves going to MDA summer camp and is seen regularly at an MDA clinic. Introduction Questions and Answers Does It Run in the Family? MDA's Search for Treatments and Cures MDA Is Here to Help You _________________ A Family Guide to the Consensus Statement for Standard of Care in Spinal Muscular Atrophy (PDF)

MDA’S SEARCH FOR TREATMENTS AND CURES

The research picture has brightened considerably for chromosome 5-linked SMA in the last decade.

There are some special circumstances that pertain to the genetics of SMN-related, chromosome 5 SMA, and these have provided researchers with some special opportunities for intervention.

Since 1995, scientists have known that the main gene that determines whether someone develops SMA is a gene for the SMN protein. The SMN gene comes in two slightly different versions, called SMN1 (also known as SMN-T) and SMN2 (also known as SMN-C).

The protein molecules made from the SMN1 gene’s instructions are longer than most of those made from the SMN2 gene. These longer ("full-length") SMN protein molecules appear to be necessary for the proper survival and function of the motor neurons.

The SMN2 gene can provide a certain amount of full-length SMN protein, but not enough. Fortunately, many people have multiple copies of the SMN2 gene on one or both of their chromosome 5s. These "extra" SMN2 genes can lessen the impact of a flaw in both SMN1 genes. In general, the more SMN2 genes a person has, the milder the course of his or her chromosome 5 SMA is likely to be.

Many research strategies to treat SMA are based on increasing production of full-length SMN from the SMN2 gene.

Other approaches include less specific methods of helping motor neurons to survive in adverse circumstances.

Drugs that are based on neurotrophic factors (natural body chemicals that have a positive effect on nerve cells) and anabolic (tissue-building) chemicals are under consideration.

Also being studied is creatine, a substance that may help muscle or nerve cells produce energy more readily.

In SBMA, research has focused largely on strategies to block the formation of abnormal clumps found inside cells in this condition; ways to interfere with some of the actions of male hormones; and methods to influence how genetic instructions are "read" by cells. (See "What Is Spinal-Bulbar Muscular Atrophy?" for more on SBMA.)

Scientists funded through MDA’s worldwide research program lead the search for potential treatments for SMA. Watch the MDA Web site and MDA’s publications for news about advances in SMA research.

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