Ramocki, M.B., Peters, S.U., Tavyev, Y.J., Zhang, F., Carvalho, C.M.B., Schaaf, C.P., Richman, R., Fang, P., Glaze, D.G., Lupski, J.R., Zoghbi, H.Y. (in press, Web Preview published). Autism and other neuropsychiatric symptoms are prevalent in individuals with MECP2 duplication syndrome. Annals of Neurology
A new study of MeCP2 duplication in boys and their mothers is already available on the web and should be in print soon.This study, however, is likely to be extremely controversial. In short the study reports: (1) boys with MeCP2 duplication syndrome fall within the narrow criteria for diagnosis of autism; (2) that mothers who carry the duplication exhibit some psychiatric symptoms that cannot be attributed to their experience of having a child with intensie needs and severe disabilities. This implies that women who carry the duplication have physical, neurological, and psychological health effects from carrying the duplication. In my opinion, the study itself is okay and even interesting, but there is a real concern that it may be misinterpreted or over interpreted.As stated in the abstract for the study:
Female carriers have psychiatric symptoms including generalized anxiety, depression, and compulsions that preceded the birth of their children. The majority exhibited features of the broad autism phenotype and had higher nonverbal compared to verbal reasoning skills.
Here are some symptoms described in mothers who carry the duplication prior to having a child with MeCP2 Duplication syndrome (parentheses indicate the number exhibiting the trait over the number sampled): High levels of anxiety (8/8), compulsive behavior (8/8), rigid personality (7/7), clinical depression (3/8), use of psychiatric medications (5/8). More than half are described as meeting he criteria for the Broad Autism Phenotype.
We need to be very cautious in interpreting this study for a number of reasons. First, we need to ask,” how does this kind of information have the potential to help women who carry the duplication?” and “how does this kind of information have the potential to do harm?” I’d be very interested to hear others’ (particularly mothers who carry the duplication) comment on these two questions. There may be some potentially helpful bits, but I also feel there is some potential for harm if these kind of findings are over-interpreted to pathologize a group of women who who have also shown themselves to be dedicated mothers and great advocates for their children.
We also need to be careful because of the scientific limitations of study. Here are some of those limitations:
1) The study is based on a very small number of carriers. There were only 9 and two were from the same family.
2) There was no random sampling of carriers. This may be important. For example, it might be that that mothers who are more dedicated and committed to trying to help their children would be more likely to be involved in the study than mothers who were less concerned with their children. There could be a strong correlation between dedication or commitment and compulsion. In fact these words can sometimes be used to describe the same behavior in positive and negative terms.
3) There is no control group. So when we read that three of eight women who carry this gene used some kind of psychiatric medication at some point in their lives we don’t know how these numbers compare to the numbers of women using these medications inthe general population, or among other comparable group. In other words we need to ask is three out of eight more than we might expect to find if we sampled the general population or if we sampled a group of women demographically similar to the mothers in this group. The use of these medications is very common among American women, and if the mothers in the study were White and Middle-class, the numbers are even higher. If there was a control group, we would likely find that 3 out of 8 is not statistically different from what we would be likely to find if we sampled the general population.
4) The Symptom Checklist 90 has been used to in other research to compare mothers of children with a wide range of disabilities to mothers of children without disabilities. Yim, Moon, Rah, and Lee (1996) compared 40 mothers of children with a wide of disabilities (cerebral palsy, down syndrome, intellectual disability, epilepsy, myopathy) to a control group of mothers of children without disabilities. Mothers of children with disabilities scored significantly higher than the control group on 5 of the 9 categories (Somatization, Depression, Anxiety, Hostility, and Phobic Anxiety) and scored higher on the remaining 4 categories (obsessive-compulsive, interpersonal sensitivity, paranoia, and psychoticism). In other words, mothers of children with disabilities(who were not likely MeCP2 carriers) received scores on the same test that were similar to the carrier mothers in the current study. This certainly suggests that caution is needed in applying the results to the genetic makeup of carriers.
Finally, it is really important to remember that the women who took part in this study were not reported to have major psychiatric symptoms or severe social adjustment problems in spite of the fact that all or almost all of them had faced major life challenges associated with having a child with severe and multiple disabilities. The focus of the study on test results must not be over-interpreted to portray these women as having something wrong with them in the absence of direct evidence based on life adjustment.
The point of these cautions is not to refute the study or to challenge the findings. I simply want to urge caution against over-interpretation of these findings. I am sure that the authors of his study would agree that these findings need to be cautiously applied at this time.
The abstract for the article is available on the Web. If you want to read the full article, you will need to purchase it from Wiley Interscience on-line or if you have access to a library that subscribes to it, you can download the article from them. For example, most University Libraries will have access. I would be interested to hear other opinions about this.
Yim, S.Y, Moon, H.W., Rah, U.W. & Lee, Y. (1996). Psychological characteristics of mothers of children with disabilities. Yonsei Medical Journal, 37(6), 380-384.