- Diseases, Disorders & Conditions
Adrenoleukodystrophy (ALD) Cured by Gene Therapy
What is Adrenoleukodystrofphy (ALD)?
Please note; the experimental therapy discussed below can not yet be claimed as a cure.
Adrenoleukodystrophy (a-dreeno-luke-o-dis-trophy) ALD.
ALD is also known as "Addison-Schilder Disease," "Siemerling-Creutzfeldt Disease," and "Schilder's disease." It is a disease (mostly in young boys) that causes progressive brain damage and disrupts the function of the adrenal glands. All of these effects are thought to be caused by a suspension of the production of myelin, the naturally occurring nerve shielding that allows nerves to carry impulses.
Without myelin nerves cannot conduct signals. Myelin can also serve as a corridor for new nerve growth to follow should a nerve be severed.
It is thought that this interruption in the production of myelin causes a breakdown in the intra-cranial signals including those in the cerebellum. Once an interruption in signals in the cerebellum occurs breathing, heart-rhythm, and other vital functions can be interfered with or interrupted, causing death.
ALD strikes children who inherit the disease from two parents who carry a faulty ALD gene. Because ALD interrupts or prevents the formation of myelin, sufferers experience brain degeneration, ataxia (lack of physical coordination), and loss of visual and auditory (hearing) function.
ALD has always culminated in the early death of the sufferer.
ALD Progression Arrested
ALD is identified in about one hundred twenty (120) boys in the United States each year. Those born with the defective ALD gene appear normal until about the fifth year of life when a catastrophic demyelinization sets in.
This often leaves the child in a vegetative state with death following shortly after. If ALD is identified before deterioration begins Lorenzo's Oil can be administered which has a delaying effect on ALD. Lorenzo's Oil is a combination of the fats from Olive and Canola oils. This combination is known to arrest the development of long chain fatty acids...the suspected cause of myelin destruction.
If deterioration has already begun the only option (up to now) is a bone marrow transplant. Of course this depends on a close match of bone marrow from a sibling or close relative.
A team of scientists at the Paris Descartes University; Drs. Nathalie Cartier and Patrick Aubourg took the healthy form of the ALD gene and inserted it into the AIDS virus. This version of AIDs virus had been "disabled" so that it cannot itself cause disease.
Because AIDS, unlike most other viruses, can insert genes into healthy static (not reproducing) cells it has lent itself to inserting corrected versions of the ALD gene into bone marrow stem cells. The result, so far, is an arrest in the progression of ALD in three boys suffering from the disease.
Dr. Theodore Friedmann of UC San Diego stated: "That's a major achievement for a field that has been in the clinic for only 18 or 19 years. . . . This is a new form of medicine and deserves to be seen as such."
Stem Cell Repair and Replacement
Drs. Cartier and Aubourg isolated bone-marrow stem cells from each of the boys, then used the retrovirus to introduce a healthy copy of the ALD gene to these cells. The bone marrow in each of the boys was then destroyed and the modified cells introduced into the interior of the bone. Fifteen percent of the newly introduced cells began producing the protein required to prevent myelin degeneration. After two years the protein continues to be produced in the patients effectively arresting the development of ALD.
The therapeutic effect of this gene-therapy is roughly equivalent to a bone marrow transplant from a healthy donor. This is good news for those patients who do not have likely donor candidates in their immediate family.
Trials will continue with larger groups including older men with milder forms of the disease.
Dr. Theodore Friedmann went on to say: "[Gene therapy] has crossed a threshold, scientifically and medically, and also in credibility, [These studies] are not hype; they are not hyperbole. They really are providing treatment for sick people."
Though the therapy described above has all the hallmarks of a cure, more trials and double-blind studies must be conducted before such a claim can be confidently made.
However, the results and careful documentation of those results are very encouraging.