PEDIATRICS Vol. 106 No. 6 December 2000, pp. 1460-1465

Carrier Testing of Children for Two X-Linked Diseases: A Retrospective Study of Comprehension of the Test Results and Social and Psychological Significance of the Testing

Outi Järvinen, MD^*, Anna-Elina Lehesjoki, MD^{, §}, Mikael Lindlöf, PhD, Antti Uutela, PhD^¶, and Helena Kääriäinen, MD^*

From the ^* Department of Medical Genetics, Family Federation of Finland, Helsinki, Finland;  Department of Medical Genetics, University of Helsinki and the ^§ Folkhälsan Institute of Genetics, Helsinki, Finland;  Helsinki University Central Hospital, HD-Laboratories, Division of Medical Genetics, Haartman Institute, Helsinki, Finland; and the ^¶ Department of Epidemiology and Health Promotion, National Public Health Institute, Helsinki, Finland.

	ABSTRACT

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Objective.  To evaluate long-term consequences of genetic carrier testing performed in childhood in terms of awareness and comprehension of the test result, and the social and psychological significance of such testing.

Study Design.  The families of 66 young females who had been tested for carriership during childhood between 1984 and 1988 were approached. Of the 66 families, 23 young females in families affected by Duchenne muscular dystrophy (DMD), 23 young females in families affected by hemophilia A (HA), and their mothers participated in our study. We used a questionnaire including multiple-choice and open-ended questions.

Results.  Of the young female participants tested in the families affected by DMD or HA, 65% knew their test results. Only 65% of DMD mothers and 78% of HA mothers remembered correctly the test results of their daughters. The majority (83%) of the young females tested sought no genetic counseling when reaching adulthood. The reason for this was not determined. Most (78%) reported that the test result had not influenced their lives, whereas some felt relieved to know they had not been carriers. Talking about hereditary disease in the family and between friends was open, and results of the carrier test had usually been told to friends.

Conclusion.  Carrier testing was in most cases correctly understood and the matter openly discussed. Our results do not suggest that testing in childhood had caused serious harm to the young individuals tested. On the other hand, we found no obvious benefits from this early testing.  Key words:  children, genetic carrier testing, X-linked disease, understanding the test result, influence of testing.

Recent advances in molecular genetics have opened up the possibility of carrier testing for a growing number of genetic disorders. Carrier status of an autosomal or X-linked recessive disease has no consequences for the individual's health, but the future offspring may be affected. It would be wise to perform such testing before a person's becoming sexually active. However, testing as early as childhood has been considered inappropriate because it may cause harm to a child's self-esteem, distortion of a family's perception of the child, deprivation of the choice whether or not to be tested in adulthood, and adverse effects on a child's capacity to form positive relationships.^1,2

The World Health Organization, in its Hereditary Disease Program, has recommended deferring testing until adulthood, to preserve a minor's future autonomy.³ The American Society of Human Genetics and the American College of Medical Genetics have stated that if medical or psychosocial benefits of the genetic test will not accrue until adulthood, as in the case of carrier status, genetic testing generally should be deferred.⁴ However, when a child is diagnosed as suffering from a hereditary disease, the parents of that child usually want to know about the carrier status of healthy siblings.⁵ They seem to consider testing in childhood important to help the children adjust to knowledge of their carrier status, as well as to allow them, when marrying, to be informed of their genetic risk.⁶ However, little is known about the experiences of those tested in childhood, how well they are aware of their test results, and how the testing procedure, in general, has affected their lives.

If genetic testing is performed on children, their parents are usually their main source of relevant information. If the parents themselves have misunderstood the result of testing, or do not remember it correctly, their children are very likely to be misinformed. According to apparently the only survey on these issues after carrier testing in childhood, this happened to only 1 of 11 tested children; the others understood their carrier status correctly.^7,8 Some studies have investigated these issues after carrier testing in adolescence.^9-13 It has been found that youthfulness may also result in misunderstanding¹² or that all of those tested do not remember the test result correctly,¹⁰ probably resulting from receiving information at a time when it is not of personal interest.

In most Western countries and also in Finland, common practice in the past until approximately 1990 was, during a genetic counseling process, to test children to discover whether they are carriers. We, therefore, had a collection of families for this retrospective study where we investigated the possible late effects of carrier testing performed 8 to 12 years previously on female children and teenagers in families with Duchenne muscular dystrophy (DMD) or Becker muscular dystrophy (BMD) and with hemophilia A (HA) or hemophilia B (HB). The aim of this study was to evaluate awareness and comprehension of the test result and the social and psychological significance of testing.

	PARTICIPANTS AND METHODS

Diseases

DMD is an X-chromosomal recessive muscular dystrophy usually leading to death in one's 20s. BMD is its less severe form, with a longer life span. Both are progressive diseases usually considered difficult and depressive for families.¹⁴ HA and HB are X-linked recessive bleeding disorders. Their prognosis has greatly improved over the past 20 years, but they still remain chronic, often serious diseases,¹⁵ requiring lifelong replacement therapy of the deficient coagulation factor.

With X-linked recessive inheritance, only males are affected, but their female relations are at risk of being carriers. Any sons of symptom-free female carriers have a 50% chance of being affected. It is possible, by genetic testing of healthy female family members, even in childhood, to determine carrier status. The 2 basic methods are direct mutation testing and linkage studies: the former confirms or excludes carriership with certainty; the latter is associated with uncertainty of varying extent.

Participants

This study was comprised of 2 groups of young women who had undergone genetic carrier testing during childhood in the 1980s in Finland, and their mothers. The parents were approached by mail by the same doctor who had counseled them at the time of testing. They were told about the study, asked whether they would be willing to participate, and also asked to inform their daughters about the study. The female participants tested were therefore contacted only via their parents. Those parents who consented received the questionnaire (1 for each parent). A questionnaire with a reply-paid envelope was also sent to those daughters who consented, provided they were at least 15 years old. If no reply had been received within 6 weeks, a reminder was sent. The letters and the questionnaires were mailed and received back between October 1996 and February 1997. Families who did not reply were subsequently contacted by telephone, and interviewed briefly; results are shown elsewhere.¹⁶

In 30 families with DMD or BMD, 39 children had been tested for carrier status in the Department of Medical Genetics, University of Helsinki, from 1984 to 1988^17,18 by means of direct mutation analysis or linkage studies. During the same period, 46 children in 38 families with HA or HB were also tested for carrier status^19,20 by means of direct mutation analysis or linkage studies (HA), or solely by means of linkage studies (HB). Those tested were sisters or female cousins of affected males. Age at the time of testing ranged from 1 to 17 years.

We restricted our study to the 66 who at the time of our study were over 15 years old, and also their mothers (46 of them participated in our study). Their ages at the time of testing are in Table 1. All the respondents were from the families with DMD or HA, none of the families with BMD or HB replied. The mean age of respondents in the families with DMD was 21.7 years (standard deviation [SD] ± 4.2 years), and in the families with HA also 21.7 years (SD ± 3.5 years). The participants had married and had children at the same rates as females of the same age in Finnish population.¹⁶

The optimal control group would have been sisters or female cousins of the affected boys who had not been tested in childhood. However, at that time almost all females in those families had been tested. Consequently, carriers, noncarriers, and those for whom the test result had been uncertain were compared with each other. Daughters' knowledge about their carrier test results was compared with the knowledge of their mothers.

Methods and Procedures

Gathering Information The questionnaire contained some 100 questions, most of them multiple-choice, and the rest open-ended. The first part consisted of items relating to sociodemographic background and life situation, and included the RAND 36-item Health Survey 1.0²¹ for measuring health-related quality of life.¹⁶ The second part had questions about satisfaction with the carrier testing and decision-making.²² For the present study, we analyzed answers relating to awareness of the test result and the social and psychological significance of reception of the genetic carrier test result. As only a few fathers replied, and it was obvious that the mothers sometimes had also filled in the questionnaires of the fathers, fathers' replies were not analyzed. Mothers who had had 2 daughters tested completed 2 questionnaires, one for each. Five mothers in the families with DMD and 2 mothers in the families with hemophilia had 2 daughters tested.

Questionnaire

1. Awareness of the Test Result Awareness and comprehension of the test result were evaluated by the following questions: "How old were you when your parents first told you the result?"; "At what age did you start to understand the meaning of the result?"; and "What was the result of the genetic carrier testing?" For the last question there were eight possible answers (I am a carrier (risk over 95%), I am at very high risk of being a carrier (90%-94%), I am at high risk of being a carrier (60%-89%), I am at moderate risk (20%-59%), I am at low risk (5%-19%), I am not a carrier (<5%), the test result remained uncertain, cannot say). The mothers were asked, "What was the result of the genetic carrier testing of your daughter?" The possible answers corresponded to those of the daughters. In addition, the daughters were asked, "Have you participated in genetic counseling?" There were three possible answers (yes, no, do not know).

2. Social and Psychological Significance Social and psychological significance was evaluated by inquiring how openly the disease and test result had been discussed within the family and with friends. This was evaluated by the following questions: "Have you told your friends about the hereditary disease in your family?"; "If your test result indicated carrier status or remained uncertain, have you told this to your friends?"; and "How often do you discuss the hereditary disease with other family members?" The first 2 questions had 5 possible answers (to all my friends, to some of my friends, to my best friend, to nobody, or cannot say). The third question had 5 (never, sometimes, usually, often, whenever necessary). The mothers were asked, "Have you told the result of the carrier testing to your daughter?" and "How did you experience telling the test result to your daughter?" The first question had 3 possible answers (yes, no, do not remember), and the second question had 5 possible answers (very difficult, difficult, cannot say, easy, and very easy).

Statistical Procedure

Respondents were divided into 6 groups based on the disease and comprehended carrier status: muscular dystrophy carrier/noncarrier/those for whom the test result remained uncertain, and hemophilia carrier/noncarrier/those for whom the result remain uncertain. The noncarrier group was comprised of those who, after having been tested, understood their risk of being a carrier to be excluded or extremely small (<5%). The carrier group was comprised of those who considered themselves to be carriers or at an over 90% risk of being carriers. The uncertain group was comprised of those who had understood that the risk of their being carriers could be neither excluded nor confirmed (risk 5%-90%), or did not know their test result. For analysis, respondents were divided based on their subjective perceptions of carrier status rather than based on any objective test result, because the former was more relevant for the questions asked.

All data analyses were done with the program Statistical Package for the Social Sciences (SPSS) for Windows version 8.0. Fisher's Exact test was used to compare mothers' experiences about telling the test result (good results vs bad results) to their daughters. A P value <.05 was considered to indicate statistical significance.

	RESULTS

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Awareness of the Test Result

In the families affected by DMD, 15 of the 23 (65%) young female participants knew their test result correctly, and 65% of the mothers also knew the result correctly. In the families affected by HA, comparable figures were 15 of 23 (65%), and 78%. Whether or not the daughters knew the test result correctly did not correlate with testing age, age at which the result was revealed, or with the education of the mothers. Three mothers in the families with DMD were incorrect about the test result of their daughters. One of these daughters was totally incorrect about her result, 1 was correct, and 1 "could not say." In addition, 1 daughter was incorrect, whereas her mother was correct. In the families with HA, 2 mothers were incorrect and so were their daughters. In addition, 2 mothers could not describe the test result, and in these families 1 of the daughters was incorrect, and the other could not tell.

In the families affected by DMD, at least 5 of 9 (56%) of the daughters tested at age 13 years or more had an incorrect memory as to the age at which the result had been revealed to them. The respective figure for the families affected by HA was 5 of 13 (38%). They incorrectly remembered the test result as having been given at an age some years younger than the age at which they actually had been tested (Table 2). The incorrect dates did not correlate with test result.

Social and Psychological Significance

Openness of Discussion of the Disease and the Carrier Status Altogether, 40 of 46 of the mothers reported that they had told the result to their daughters, 2 of them just after receiving the questionnaire. One daughter who had not been told had come to know the result some years after the testing in the course of genetic counseling when planning a pregnancy. Another tested daughter had been counseled in a genetic counseling clinic just after carrier testing. Although the remaining 4 daughters had not been told their test result, their parents gave them the questionnaire, and they participated in our study. Three of them reported that they did not know the test result. One daughter thought that she might be a carrier, and actually she was. What the mothers reported about their experiences about telling the test result of testing to their daughters, is shown in Table 3. Telling the good result (noncarrier) was statistically significant easier than telling the bad result (carrier or uncertain) (P value = .017), Table 4.

Consequences of the Test Result

In the families with DMD, 18 of 23 (78%) daughters felt that the genetic carrier testing had not influenced their lives. Two reported positive effects: 1 noncarrier reported that it was a relief to know that she was not a carrier, and 1 member of the uncertain group found it possible to adapt to the situation. Two reported negative effects: "The time to have children is postponed to the future" (1 carrier and 1 member of the uncertain group), and "If I am going to have a child, I will now have more trouble than people usually have when they bear a child, because I am a carrier". In the families with HA, also 18 of 23 (78%) participants reported no influence. Four reported a positive influence, valuing the possibility to adapt to the situation (3 members of the uncertain group), and being sure that there was no risk (1 noncarrier). One member of the uncertain group reported a negative influence: "I am not sure if I ever want a child." All considered that their parents had not treated them as different from their sisters or brothers because of the test result.

Participating in Genetic Counseling

In the families affected by DMD,18 of 23 (78%) had not been counseled in a genetic counseling clinic; the rest, 5 of 23 (22%), had been. In the families affected by HA, the respective figures were 20 of 23 (87%) and 3 of 23 (13%).

	DISCUSSION

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This study showed that 65% of young female participants tested in families affected by DMD or HA knew the test result correctly 10 years after the test. Only 65% of DMD mothers and 78% of HA mothers remembered the result correctly. If the parents are the only source of information, and if they have misunderstood or do not remember the test result, their children get the wrong information. This was apparently the case in 13 of 46 of families in this study. There was incorrect recall despite the fact that the result had always been given also in written form. This problem could be lessened if it were strongly recommended to mothers to contact the genetic clinic whenever they feel uncertainty about understanding test results. The phenomenon that the mother had passed wrong information on to the daughter was more rare (1 of 11) in another study.⁸

When carrier screening or testing has been performed on adolescents or even adults, a small proportion have always misunderstood the results^11,12,23-26 or recalled them incorrectly.^10,11,26-29 In this respect, our data on tested children does not differ from findings on adolescents or adults. Somer et al, evaluating postcounseling knowledge in families, found that knowledge of recurrence risk was poorest for cases of X-linked transmission.³⁰ Compared with their figures, the rate of misunderstanding in our study was no higher. That so many DMD and HA daughters tested at age 13 or more incorrectly remembered the age when they had been told the test result probably indicates that in their teen years the result was not of personal interest.

Why the great majority had not been counseled in a genetic counseling clinic was not explored. We know that many of them (48%) were married or lived permanently with a partner, and some (20%) already had children.¹⁶ As the carrier testing had mainly been conducted by linkage, at least some uncertainty as to carrier status had remained for the majority of the subjects. Contrary to what might be expected, very few had sought for the services of genetic counseling. In fact it seems that testing in childhood not only deprives one of the choice of autonomous decision-making in adulthood but, in addition, somehow also prevents one from the desire to ask for genetic counseling.

Most respondents reported that the test result had not influenced their lives, although some reported that it had been a relief to know they were not carriers. Three carriers reported that they were not sure whether they wanted children at all. In our earlier study, the emotional, social, and physical well-being of the these same tested daughters was at least as good as that of the controls measured by RAND.¹⁶ Their subjective report that carrier testing had not influenced their lives was consistent with the objective evaluation by RAND. It has been argued that a child may be treated differently if its carrier status is known. This was not the experience of the respondents in our present study, nor found in the only earlier study.⁸

The discussion of hereditary disease in the family and between friends was reported to have been open, and results of the carrier test had usually been told to friends, a result similar to the finding of an American study in which 94% of carrier couples thought it unnecessary to keep it a secret and were prepared to discuss it freely with anyone.³¹ However, the fact that altogether 13 mothers reported that telling the result had been difficult, and that there were mothers who had not even told the results to their daughters, or that several years had passed before the result had been told showed that passing on the information had often been problematic. Particular problems can arise if more than 1 sibling is tested, and they receive differing results.³² These problems came out in our study also.

We are aware that there are several limitations in our study. In Finland, genetic carrier testing was actively offered to the great majority of X-linked muscular dystrophy and hemophilia families in the 1980s, and practically all sisters and female cousins of the affected boys were tested. We were able to trace most families concerned. Despite this, our study population was quite small, and therefore it was not possible to go into detail on the mechanisms of background, (eg, by multivariate analysis). The questions used had high face validity, but by an interview it might be possible to gather more in-depth information. One shortcoming of our study is that those daughters who had not been told the test result were overrepresented in the group who did not participate and fill in the questionnaire. The fact that there were no control families is also a shortcoming.

According to our study, 65% of those tested in childhood and who had been told their test result, had correctly understood the carrier test result. The respondents reported that the matter had been openly discussed in families and between friends. Such discussions can mean that carrier testing in childhood caused no serious problems. However, revealing the result was often experienced by the mothers as very difficult. The tested daughters had made use of genetic counseling services remarkably seldom. Our results do not suggest that testing in childhood caused serious harm. On the other hand, they do not reveal any obvious benefits of early testing. At present, it is generally agreed that genetic carrier testing should be deferred until adulthood.^1,3,4 We agree with this. If, however, testing of children is performed, the procedure should include counseling of the families initially, supporting them in informing their children about the disease and the test result, as well as offering genetic counseling for the children when they reach adulthood.

	ACKNOWLEDGMENTS

This study was supported by grants from the Academy of Finland.

We also wish to thank all the families and young female participants who took part in this study.

	FOOTNOTES

Received for publication Jul 8, 1999; accepted Feb 22, 2000.

Reprint requests to (O.J.) Department of Medical Genetics, Family Federation of Finland, Box 849, FIN-00101 Helsinki, Finland. E-mail: outi.jarvinen{at}vaestoliitto.fi

	ABBREVIATIONS

DMD, Duchenne muscular dystrophy; BDM, Becker muscular dystrophy; HA, hemophilia A; HB, hemophilia B; SD, standard deviation.

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