Jun17

Written by:
6/17/2010 12:14 AM 

Nail–patella syndrome is a rare genetic disease caused by a mutation in a portion of chromosome number 9 and occurs in about one in 50,000 individuals. The genetic defect causes abnormalities in connective tissue metabolism and structural defects in collagen, and is inherited as an autosomal dominant trait. This means that it is not associated with the chromosomes that determine gender and is therefore not found more frequently in one or the other gender, and that, if the mutation is present in one parent, the disease will be present in at least half of the children as well.

Nail-patella syndrome causes fingernail abnormalities, primarily absent or under developed thumbnails, absent or under developed patellae, or knee caps, pelvic abnormalities, and deformation or abnormal development of the radial heads, or bones in the forearms, and in other joints. Nail-patella syndrome is also associated with kidney disease and glaucoma. How the association with glaucoma was discovered is an example of how medical knowledge is sometimes advanced by coincidence and luck, Dr. Paul Lichter, a physician at the University of Michigan Kellogg Eye Center, noticed that a glaucoma patient he was treating had no thumbnails and abnormal knee caps, and remembered that the patient’s mother, whom he had treated many years before, had the same conditions. Both patients had nail-patella syndrome, as did 24 other members of their extended families, more than 50% of whom also had glaucoma. Genetic analysis of these patients showed that the genes associated with their glaucoma are also located on chromosome number 9, in the same area of the chromosome called 9q34, where the mutation associated with nail-patella syndrome is located. Around 50% of all nail-patella syndrome patients also have glaucoma, though it is not known whether the genetic defect that causes nail-patella syndrome also causes the glaucoma. Kidney disease is often part of the syndrome as well, affecting about 40% of patients and leading to kidney failure in about 10% of them.

Severe pain due to joint malformations and instability is common in nail-patella syndrome, and treatment is typically to try to reduce the severity of the symptoms, to reduce the pressure within the eye if the patient has glaucoma, and to prevent any kidney problems from progressing to renal failure. As we’ve seen, marijuana can be used to reduce eye pressure in glaucoma and is very effective in treating pain. It is important to note that marijuana can be recommended for both conditions in Colorado as well, even though nail-patella syndrome is not specifically mentioned in Article.18 of the Constitution.

How is it that specific diseases are included in the laws of some states and not in others? At least in the case of Michigan, it seems that special interest groups and individuals with nail-patella syndrome successfully lobbied the legislature to include it by name in the legislation. Indeed, most states with medical marijuana laws have provided for a process by which new conditions can be added to the approved list. In Colorado, patients or physicians may petition the Department of Health to have new conditions added. Several such petitions have been filed in Colorado, but to date, none have been approved. According to press reports, this has been because the medical research on the use of cannabis in those conditions has been found to be inconclusive, incomplete or less than definitive.

Sometimes, however, medical authorities disagree about whether research supports the use of cannabis or not. According to a New York Times article of March 24, 2010, that is exactly what happened in the case of PTSD, which was designated an approved condition in New Mexico in February, 2009, but was narrowly rejected in a vote in a committee of the Colorado House of Representatives in March of this year. A medical advisory committee in New Mexico recommended that PTSD be approved because “…marijuana could help relieve anxiety associated with post-traumatic stress disorder,” and went on to cite a number of psychiatric and pharmacological studies they felt supported its use. The Times article quotes Dr. Alfredo Vigil, the secretary of the New Mexico Department of Health, as saying “There are hints and some indications in the medical literature that there are components of cannabis that might be helpful to some people with P.T.S.D.” However, the article also quotes Dr. Ned Calonge, the chief medical officer for the Colorado health department, as saying that the psychiatry departments at the Veterans Affairs hospital in Denver and the University of Colorado School of Medicine agreed that marijuana should not be recommended for treating PTSD, saying “There is no evidence of efficacy of marijuana for treatment of P.T.S.D. in the medical literature.” Dr. Colonge also said that “…some clinical evidence supports the drug’s effectiveness in treating those conditions for which medical marijuana is already approved in Colorado.”

Clearly, there is disagreement even among medical authorities about how to interpret medical research. According to Dr. Vigil, “All of these states are going out on a limb, trying to determine from a medical, clinical point of view, what seems reasonable.” It should be noted that more than 25% of medical marijuana patients in New Mexico were approved for use of marijuana to treat PTSD.

Please join us next week as we continue to discuss conditions for which marijuana may be recommended in other states.