PREIMPLANTATION GENDER DETERMINATION AND X-LINKED AUTISTIC BEHAVIOR
Shinji Ijichi, M.D. & Naomi Ijichi, M.D.
June, 1996
Autism can be conceptualiszed as a biologically determined behavioural syndrome with multiple etiology. In some of the patients, the autistic behaviors may be associated with a series of complicated genetic traits and some of the genetic determinants which facilitate the autistic phenotype may be on the X-chromosome.
Recently, a combination of molecular technologies and assisted reproductive procedures provided a possibility of delivering female babies free from the phenotype of X-linked genetic traits for carrier mothers (1-3). However, the ethical, legal, social and philosophical implications of the disease control process raise a lot of subtle controversies (4).
The medical ethics committee in Kagoshima University has been considering a proposed application of the preimplantation sexing for exclusion of human male embryos, 50% of which have the disease genetic trait, to offer an alternative reproductive option for the parents at risk of having offspring affected with X-linked genetic disorders. So far, the committee decided to restrict the application to the preimplantation prevention of Duchenne muscular dystrophy and announced that technical and statistical details should be open to the public and the public agreement on the ethical aspects is a prerequisite. These activities elicited many comments from associations and individuals and highlighted the presence of critical and opponent opinions by patients associations except muscular dystrophy community. The point at issue is that the exclusion of affected embryos might facilitate the discrimination and the prejudiced view against patients.
In the near future, the application of this single-blastomere analysis will enable the preimplantation diagnosis of conditions determined by multiple genetic factors (5). These may include cognitive, behavioral, or developmental disorders. In fact, fragile X syndrome, characterized by mental retardation and frequent concomitance of behavioral disorders including autistic tendencies, was involved in the initial discussion in the university medical ethics committee in Kagoshima. In addition, we should consider that disabilities, impairments, and deficits in socialization are often referred to as personal qualities of the individuals in the revolution of social welfare for disabled persons, a movement called 'normalization' or 'inclusion'. Therefore, the decreasing distance or obscured distinction between 'quality control' and 'disease control' should be get more attention in the implications of gene testing and therapy. We need to insure that the proposed research in this field is subject to full and open debate 'disease by disease' and importantly that the discussion is participated in by patients with each diseases, the relatives, and clinical practitioners who know the entire course of the disease as well as scientists and the technical staff concerned.
References
1. Handyside AH, Kontogianni EH, Hardy K, Winston RM. Pregnancies from biopsied human preimplantation embryos sexed by Y-specific DNA amplification. Nature 1990; 344: 768-70.
2. Munne S, Tang YX, Grifo J, Rosenwaks Z, Cohen J. Sex determination of human embryos using the polymerase chain reaction and confirmation by fluorescence in situ hybridization. Fertil Steril 1994; 61: 111-7.
3. Verlinsky Y, Rechitsky S, Freidine M, Cieslak J, Strom C, Lifchez A. Birth of a healthy girl after preimplantation gender determination using a combination of polymerase chain reaction and fluorescent in situ hybridization analysis. Fertil Steril 1996; 65: 358-60.
4. Raeburn JA. Preimplantation diagnosis raises a philosophical dilemma. BMJ 1995; 311: 540.
5. Snabes MC, Chong SS, Subramanian SB, Kristjansson K, DiSepio D, Hughes MR. Preimplantation single-cell analysis of multiple genetic loci by whole-genome amplification. Proc Natl Acad Sci USA 1994; 91: 6181-5.
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