Clinical judgement still counts strongly alongside genetic testing

Suggestions that genetic tests are taken more into account than a doctor’s clinical judgement are dismissed in new research sponsored by the ESRC and published as part of Social Science week.

And clinicians do not adopt a ‘blunderbuss’ or ‘grape-shot’ approach. Appropriate tests are ordered in the light of clinical decisions and differing diagnoses, according to the study led by Dr Joanna Latimer, of the School of Social Science, Cardiff University.

The findings are the result of a one-year, intensive case-study of dysmorphology – a specialty in clinical genetics which involves spotting disorders affecting physical development, before or after birth.It includes recognising particular patterns of physical features in patients with a range of problems or ‘troubles’, sometimes including delayed intellectual development.

Patients are mainly babies, children and teenagers or young adults, and genetic services are involved because the majority of these syndromes have a genetic basis. Dr Latimer said: “While there are an increasing number of laboratory examinations that can be made to investigate possible dysmorphic conditions – including DNA and chromosome testing – it is not the case that these are supplanting clinical expertise. Laboratory tests do not simply outweigh clinical evidence.”

She continued: “The relationship between how the patient’s condition reveals itself and the underlying DNA or chromosome evidence is not entirely predictable.”

“Many syndromes are rare and complex, and the laboratory-based technology is not yet available with which to make their genetic basis visible. What we have found is that other, clinic-based techniques and technologies, such as photographs and family trees, have developed with which to do genetic profiling, and which help in distinguishing genetic conditions from other kinds of problems.”

The study found that locally, nationally and internationally specialists in dysmorphology are recognised by their professional peers as having knowledge and authority in the field. The field of dysmorphology embraces on the one hand the new medical technologies being employed and interpreted, and on the other the long-standing features of clinical medicine.

Interviews with families of dysmorphic children revealed that, for some, identifiying a genetic reason for various problems and delay in development can provide a source of satisfaction. It can remove doubt and uncertainty as to the condition itself.

Some parents have real concerns over the possibility that they are in some way responsible for their children’s problems. In particular they worry whether their lifestyle choices, such as smoking in pregnancy, are the cause of their child’s troubles.

Identifying a genetic condition, whether inherited or a sudden occurrence, exonerated parents over their child’s problems and alleviated their feelings of guilt and responsibility.In addition, a ‘medical label’ provides access to support and resources, including educational and other medical services.

For other families, however, identifying a genetic cause for the child’s disorder can result in more unclear reactions, or even real distress. Again, the reasons for this response are complex, including what the study calls the ‘death of hope’, because a genetic diagnosis can confirm that a child’s troubles cannot be reversed or repaired.

And a genetic diagnosis may include a poor prognosis, or be seen to have grave ramifications for other, including future, family members.