MLL is not a nasty leukemia-causing protein. In fact, it is just the opposite. Cell division is somewhat like moving into a new apartment – all the DNA is still neatly packaged into moving boxes. By labeling genes immediately after division, MLL helps avoid potential errors in the operation of new cell.  Comparing cell division to Moving Day – all the DNA is still neatly packaged into moving boxes – it may become clear that labeling genes that are needed immediately may be a helpful trait to avoid hick-ups in a new cell’s operation. Just like labeling the moving box with the shampoo and the slippers might allow us to function efficiently at the evening of Moving Day. Just saying…

Elucidating MLL’s function adds to our knowledge about how information is being passed from one generation to the next. Mechanisms such as this operate on top of the genetic code and belong to a cell’s arsenal of epigenetics tricks. MLL confers information by sitting on genes that need to be activated, making sure the cell finds them quickly.

Mutated forms of MLL, however, can cause leukemia (among a slew of other troubles). Check out the story about another gene involved in chronic myeloid leukemia in Genes and Medicine at http://www.dnai.org/d/index.html.

Progeria is a very rare, genetic disorder that afflicts roughly one in 5 million people. It is caused by a mutation in the LaminA gene on chromosome 1. The most striking symptom of Progeria-afflicted children is that they age rapidly. They frequently succumb to coronary artery disease before they reach 20 years of age.

Directed by R Balakrishnan the Indian movie company AB Corp Ltd. has released the movie “Paa”. The picture’s protagonist is a 13-year old boy afflicted with progeria – and is being played by an actor who is actually in his 60s. AB Corp Ltd. proclaims that Paa is not a movie about the disease Progeria, but about “how special children can fill your life with special brightness.”

Read more: about Progeria at the Progeria Research Foundation; about living with serious genetic disorders at the DNALC’s Your Genes, Your Health site.

The underlying cause for FXTAS is a mutation in the gene for Fragile X Mental Retardation Protein (FMRP), which is located on the X-chromosome; its protein product, Pur-α is essential for normal neural function. Scientists have recently determined the three-dimensional structure for this protein, a first step in the potential identification of an effective treatment that would address the cause and not just the symptoms of FXTAS.

As described in Your Genes, Your Health, the gene contains a region that consists of repeated CGG DNA triplets. In healthy people, both copies of their FMRP gene contain 5-54 copies of the CGG triplet. Disorder manifests itself if the repeat numbers exceed 54 in both gene copies (the disorder is recessive): 55-200 repeats lead to FXTAS, as described above. Repeat numbers exceeding 200 lead to Fragile X Syndrome (FXS), the second most common cause of heritable mental impairment after Down’s syndrome.

Given that the symptoms of FXTAS include shaking hands, it is interesting that the authors describe the shape of the FMRP protein, Pur-α as: “The crystal structure of Pur-α … looks like a hand: four so-called beta-strands, corresponding to four fingers, form a beta-sheet, and an adjacent alpha-helix resembles a thumb.” Apparently, pairs of PUR repeats bind to each other in a configuration that is reminiscent of a handshake, forming a functional unit that binds to RNA.

Just recently, a group of researchers at the University of Maryland School of Medicine have identified a variant of a gene that is believed to play a major role in determining why people do not respond to a popular anti-clotting medication. This gene variant, carried by as many as a third of the general population can put patients at increased risk for subsequent heart attacks, strokes and other serious cardiovascular problems. The interesting thing is, that this increased risk is not due to patients genetic predisposition for these disorders, but because it renders their medication ineffective.

Medicines that we introduce into our bodies often require one or several important mechanisms to unfold their intended effects: they may have to be actively transported into our cells, biochemically altered and thereby activated, or they may require deactivation and/or removal in order to not do more harm then good. Any of these processes may involve proteins on one level or another and, therefore, depend on genes. Thus, as we have maps that indicate the loci associated with genetic disorders (visit Tour > genome spots in DNA Interactive), we will soon have maps that tell us where to look if we wish to know our predisposition to the medications we use to cure ailments: whether they will do us any good, are totally useless or, in a worst case scenario, can even harm us.