492 Letters to the Editor

cussion in the report puts this very properly issues until too late. I will be disappointed if The genetic testing of into context. The report is clearly opposed to GIG interprets this caution on the part of the children the idea that genetic testing could be used to CGS Working Party as an indication that we judge the suitability of a child for adoption. are patronising towards parents. When the I am happy to have the opportunity to com- As regards children in care, their position GIG working party's "principles" are some- ment on the response from the Genetic In- is legally the same as any other child; parental what more prescriptive than our "re- J Med Genet: first published as 10.1136/jmg.32.6.492 on 1 June 1995. Downloaded from terest Group (GIG) Working Party to the responsibility may not be held by the bio- commendations" I am not sure that this Report of the Clinical Genetics Society's logical parents, but this does not alter the attribution is entirely fair. (CGS) Working Party on the genetic testing of moral or legal responsibilities of the "par- In conclusion, this document from GIG is children. I was chairman ofthe CGS Working ents". Adoption is quite different because a very helpful contribution to the debate on Party, but here I am presenting my own views. of an imminent change in identity of the these issues. It is striking how similar the I am very pleased that the CGS report has "parents". GIG statements of principle are to the CGS stimulated discussion among families and the document's recommendations, although GIG, and the five statements of principle set 2.5 PRENATAL TESTING there are some differences. It is also striking out in the GIG document will provide a most The meaning of this principle is not entirely how much common ground there is between useful reference for future debate. I would clear, although I sympathise with the GIG both documents and the reports from Wertz like to comment on these principles. working party in stating it. Should carrier et al' and Andrews et al.2 status for a genetic disorder be imparted to 2.1 CHILDHOOD ONSET CONDITIONS parents undergoing prenatal diagnosis for a ANGUS CLARKE The CGS report clearly states that testing for recessive condition, or should they simply be Institute of Medical Genetics, childhood onset disorders was excluded from told that the child will or will not be affected? University of Wales College ofMedicine, Heath Park, Cardiff CF4 4XN, consideration, because the ethical and prac- Principle 2.2 does not help. Should parents UK tical concerns that abound in relation to test- only be offered prenatal testing for a late ing for late onset disorders simply do not onset disorder on the condition that they apply. There do remain problems ofdefinition terminate an affected fetus? Principle 2.1 does 1 Wertz DC, Fanos JH, Reilly PR. Genetic testing (what is a childhood onset condition?) but not help. I understand the points made in the in children and adolescents: who decides? as a general policy I fully endorse the GIG GIG document but the applications of the J3AMA 1994;272:875-81. 2 Andrews LB, Fullarton JE, Holtzmann NA, approach. Their concern that the CGS report principle would appear somewhat opaque. Motulsky AG, eds. Assessing genetic risks - im- equivocates on this is misplaced. When pre- plicationsfor health and socialpolicy. Washington dictive testing in childhood for an adult onset The statement of these five principles will DC: National Academy Press, 1994. disorder is being considered, and if the med- prove most useful in providing a focus for ical benefits of presymptomatic diagnosis in future discussion. It is certainly interesting childhood are unclear, then the results of that the GIG working party took a very firm pyschosocial evaluations of childhood testing stand against predictive testing for adult onset Possible genetic may well be critical for certain medically disorders, but took a much less clear position heterogeneity in "borderline" cases. This statement was never in relation to carrier testing. intended to apply to childhood onset con- Perhaps this reflects the differences ofopin- hypochondroplasia ditions, and I feel that the GIG criticisms ion among parents on this issue, as the CGS reflect a simple misunderstanding on this report reflected differences of opinion among Segregation analysis in families with hypo- point. professionals. chondroplasia indicates that at least some Finally, let me turn to section 1 of the GIG cases of the condition result from mutations 2.2 TESTING FOR CARRIER STATUS report. I have read and re-read the relevant in a gene other than FGFR3 and suggests This principle concerning carrier testing is sections of the CGS report (section 5 and that hypochondroplasia is genetically het- problematical. The phrasing suggests that appendix 3) relating to the questions that erogeneous. Mutation analysis shows that the parents only have a right to have the carrier the CGS Working Party sent around GIG G380R substitution in the FGFR3 is not the status oftheir child determined "after suitable in member organisations. I remain mystified underlying cause hypochondroplasia. http://jmg.bmj.com/ counselling" and after making an "informed why the GIG response states that the CGS Hypochondroplasia is an autosomal dom- choice". These qualifications, however, re- report is partronising towards GIG members, inant disorder characterised by short limbed quire a clear understanding of "suitable coun- that the consultation with them was poor, dwarfism (rhizomelic type), lumbar lordosis, selling" and "informed choice". And if a and that GIG and its members were badly short and broad bones, and caudad narrowing professional sincerely believes that testing a represented. The questions sent around GIG of the interpediculate distance of the lumbar particular child would place them at risk of were very straightforward, and our reporting spine.' The phenotype of hypochondroplasia harm, do they have an obligation nevertheless of the various responses was also straight- is similar to that ofachondroplasia but milder. to carry out the test? If not, what force does forward. It was also quantified as far as the The two conditions have been thought to be the word "right" carry? If counselling is to be data permitted. Perhaps someone needs to allelic.2 Recently, achondroplasia was loc- on October 4, 2021 by guest. Protected copyright. a hoop through which a determined parent take me to one side and point out (gently, alised on the short arm of chromosome 4 has to jump in order to have their child tested, please) just how patronising the report was. (4p16.3)35 and its molecular basis was then the counselling is being enforced and The GIG response also states that the tone elucidated.67 A G-.A transition at nucleotide will be worthless. of the CGS report is patronising to parents. 1138 of the gene encoding fibroblast growth I would endorse the second sentence in the I deeply regret this, if this is a widespread factor receptor 3 (FGFR3) was identified in principle 2.2 and would wish to strengthen it perception. I would not be so surprised if 58 of 62 achondroplasia chromosomes stud- by deleting the word "ideally" and inserting medical colleagues in paediatrics or haem- ied.6" This mutation results in a G380R the word "fully", thus: "Children should only atology regarded the report as patronising, substitution in the transmembrane domain be tested when of an age to be fully involved because it does suggest that there is a real of the FGFR3. This remarkable phenotype- in the decision." Does not this sentence in danger ofinappropriate genetic testing ofchil- genotype correlation and the assertion by Le fact contradict the preceding one? dren becoming widespread as access to such Merrer et al' that hypochondroplasia maps in same as achon- 2.3 ADULT ONSET CONDITIONS tests becomes simpler and bypasses clinical the chromosome region available com- prompted us to further The GIG statement ofthis principle is a shade geneticists, perhaps becoming droplasia investigate No doubt these the between stronger than the working party re- mercially. professional groups relationship hypochondroplasia commendation. It is difficult to reconcile the will learn from their mistakes, as geneticists and FGFR3. have but a lot of harm could be done We studied a panel of eight two and three GIG wording with the notion that each case done, this generation families in which hypochondro- should be considered individually, a notion by inappropriate testing during learning I would that these medical plasia segregated as an autosomal dominant which both working parties seem to respect, process. hope will find the to be trait. At least one affected person in each of and the laying down of such a firm principle colleagues report helpful could be legally vulnerable. rather than patronising, but I could un- the eight families was studied. The G380R derstand some of them regarding it in that mutation was not detected in any of the eight 2.4 ADOPTION light. In so far as recommendations need to hypochondroplasia chromosomes tested. In The CGS Working Party report does not be framed so as to protect children from addition we genotyped the hypochondro- "leave loopholes" for adoption, but simply genetic testing by anyone, it is from testing plasia families with the D4S227, D4S115, states that judgements of a child's best in- carried out without adequate previous con- D4S 1 14, and D4S43 markers which flank the terests may be more complex if the child is sideration or discussion by a professional who FGFR3 gene and have been mapped to a being considered for adoption. The dis- may not be alert to the complexity of the 2-5Mb distance in the telomeric region of