In the last ten years, a novel approach to the clinical care of persons with genetic disorders and congenital malformations has emerged from the disciplines of medical genetics and pediatrics. This model consists of the rational development of guidelines for routine medical care, screening, and follow up of individuals with syndromes. This particular notion is not unique as multidisciplinary clinics caring for persons with complicated disorders have been dealing with these issues for years. The novel concept here relates to the adaptation of guidelines taken from a well-child model to infants and children with genetic disorders. The strategy actually implies that the primary care practitioner has a definite role in orchestrating such care and in most circumstances actually represents the primary manager. This author has summarized the basic principles surrounding this model of health supervision and anticipatory guidance for children with genetic disorders in a recent review and position paper (Carey, 1992). The purpose, then, of this report is simply to apply that model in more detail to the care of children with trisomy 18 and 13 and present these suggestions in tabular form.

Given the survival figures for trisomy 18 and 13, one might posit that the development of such guidelines is unnecessary. The author has chosen to propose these suggestions for two reasons: First, although many children with trisomy 18 and 13 do not survive the first year of life, the pediatric care provider has the opportunity to help families in these situations and this guidance is really a prototype for the concept of anticipatory guidance in its fullest meaning. The theme of ongoing psychological support is also exemplified by a discussion of the care of a child with trtsomy 18 and 13. Second, for the children who do survive the newborn period, discussion of care issues is obviously important for those families, infants, and their doctors. Many of these suggestions have come from the experience with the annual conferences of the Support Organization for Trisomy 18, 13 and related disorders (SOFT).

The reader is referred to the discussion of the natural history issues in trisomy 18 in the above mentioned paper. Most of the issues regarding natural history, developmental disability, and medical complications of trisomy 18 apply almost identically to trisomy 13. The major differences primarily involve the different patterns of malformation in trisomy 18 and 13. This difference includes the type of heart defect that is present in the respective conditions as well as the potential presence of the holoprosencephaly defect in children with tnsomy 13. This central nervous system malformation may be a factor in the survival of infants with trisomy 13. To say it another way, the presence of semilobar or alobar holoprosencephaly may in and of itself be related to the early infancy death in children with trisomy 13. If this is the case, then the absence of this finding might be important in the early medical care of a child with trisomy 13. (For specifics on mortality figures and life tablesin trisomy 18 and 13 see the paper in Pediatric Clinics and the discussion in the research summaries later of this newsletter.)

The Table is meant to provide a framework and checklist for medical care, follow up and screening of infants and children with trisomy 18 and 13. Note in reviewing the Table that precise figures for most medical complications are unknown. Baty, et al. did present data at the 1989 American Society of Human Genetics summarizing the medical complications from a questionnaire study of over a hundred families of children with trisomy 18 and 13. This presentation is in abstract form and to our knowledge is the only detailed look at some of these medical complications other than the usual textbook listing of congenital malformations (Baty BJ, et al. 1989).

Also note that the issues surrounding medical care in infants with trisomy 18 and 13 are exceedingly complex. This is primarily due to the high mortality in children with both syndromes. It is important to recall, however, that about 5-10% of children with trisomy 18 and 13 do survive infancy and thus, precipitate the need for discussion of these issues. Very few generalizations can be made about decision making in infants or older children with trisomy 18 and 13. Each case must be taken on an individual basis and the practitioner must acknowledge the personal feelings of the parents, as well as the individual circumstances of each child. Although many children with these syndromes do not survive infancy, it is important to review with the parents the expected clinical course of the condition and to prepare a management plan for those who do go home. The author has found that the theme of ~best interest of the child" helps as a guiding principle in decision making throughout life. From the experiences of discussing these issues with parents of children with trisomy 18 and 13, there appear to be three themes that continue to emerge:

1. It is important to recall that about five to ten percent of children with these syndromes do survive the first year of life; thus, the condition is not universally "lethal." Parents often remark that the condition is often labeled as invariably lethal, especially in the prenatal scenario.
2. While the developmental disability in children with trisomy 18 and 13 is significant, it is important to recognize that children do advance to some degree in their milestones. Children with trisomy 18 and 13 smile, interact with their family, do not regress, and when there is survival past infancy, acquire skills such as rolling, self-feeding. signs. Thus, generalizations that "these" children do not ever interact with their family does not match the experience with older infants (see discussion of abstract at International Congress of Human Genetics, by Baty, et al, below).
3. Families in these situations appreciate the opportunity to participate in the decision making.

The care and support of a family of a child with a serious chromosomal disorder is both a challenge and an opportunity. The Table
has obviously simplified the complicated day-to-day aspects ofcopmg with the impact of trisomy 18 or 13. The author however, recognizes the unique and crucial role of primary care practitioners in care-taking.

References:
Baty BJ et al (1989): A Natural History Study of Trisomy 18 and
13.Am J Hum Gen 45:71A.
Carey JC (1992): Health Supervision and Anticipatory Guidance for Children with Genetic Disorders (Including Specific Recommendations for Trisomy 21, Trisomy 18, and Neurofibromatosis I). Pediatr Clinics of North America 39:25-53.
Faucette KJ et al (1991): Trisomy 18 and Wilms Tumor: is there an association? Clin Res 39:96A.