Folate and vitamin B12 might alleviate SMA symptoms

A new study done by researchers at the University of Pennsylvania School of Medicine suggests that folic acid and Vitamins B12 may limit the severity of symptoms that afflict patients suffering from spinal muscular atrophy (SMA). "We are not suggesting that this is a cure. But it may help,"​ said Gideon Dreyfuss, PhD, Isaac Norris Professor of Biochemistry and a Howard Hughes Medical Institute Investigator at Penn, and principal author of the study. SMA afflicts one of every 6,000-to-10,000 people and is the leading genetic killer of children under the age of two. Its symptoms include muscle weakness and wasting. The symptoms differ in severity from person to person across a range of debilitation that scientists still cannot explain fully. SMA patients have a genetic deficiency in a protein called Survival of Motor Neurons (SMN). This protein is a "housekeeping"​ protein required by all cells, especially by motor neurons that control the activity of muscles. When the levels of the SMN protein are too low, motor neurons are the first cells to degenerate, in turn leaving the major muscle groups without the stimulation they need to be viable. In their research, researchers at the University of Pennsylvania have been studying what makes SMN interact with its partners in the cell. The scientists observed that SMN will bind efficiently and carry out its functions if the proteins to which it needs to bind are first "tagged"​ by specific enzymes. The tags are made up of methyl groups that are attached through the amino acid arginine to specific sites on SMN's protein targets through a process called "methylation"​. In addition to unravelling the function of the methylation of arginines in proteins, the findings may have important implications for neuro-degenerative diseases. The methyl group tags are supplied by a "methyl donor"​ called S-adensylmethionine, which receives this methyl group from folic acid through a pathway requiring vitamin B12. According to the researchers, this raises the possibility that deficiency in folate or the B vitamins could be particularly detrimental to SMA patients, because it could result in under-methylated proteins, which are exactly the kind of proteins SMN needs to find to function properly. "We would like to say, very cautiously, that our work raises the possibility that folic acid, and vitamin B12 may be helpful in lessening, even if only slightly, the severity of the disease for some SMA patients, or at least ensure that their condition is not worse than their genetics dictate,"​ Dreyfuss said. He cautioned against putting forth folic acid and the B vitamins as a "cure"​ for the disease, noting that his team's findings are based on laboratory biochemical studies, which point the way to animal and/or human studies that need to be done before any clinical or therapeutic implications are drawn. "Certainly, we hope clinical studies will be initiated to see whether folate and the B vitamins make a difference for SMA patients that extends beyond laboratory research,"​ he said. Source: University Of Pennsylvania Medical Center​