Genetic Counseling-a core activity of genetic programs.
Genetic counselling is one of the core activities in clinical genetics. It is inseparably linked with genetic screening and prenatal diagnosis & management. Unfortunately this important aspect has not been adequately addressed in India. There is acute shortage of well designed courses in genetic counselling; this has resulted in shortage of properly trained genetic counsellors.
The whole process is mirrors the questions posed by ancient philosopher Paul Gaugin,
What is wrong? (the diagnosis),
What is going to happen? Natural history, prognosis),
What can be done? (management),
Why did it happen? (Prevention, progress).
The committee of American Society of Human Genetics defined Genetic counselling as follows,
Genetic counselling is a communication process which deals with the human problems associated with the occurrence, or the risk of occurrence, of genetic disorder in a family. This process involves an attempt by one or more appropriately trained persons to help the individual or family to
Comprehend the medical facts, including diagnosis, probable course of the disorder and available management,
Appreciate the way heredity contributes to the disorder and the risk of recurrence in relatives
Understand the alternatives for dealing with the risk of recurrence,
Choose the course of action which seems to them appropriate in view of their risk, family goals, ethical & religious standards, to act according to that decision,
To make the best possible adjustments to the disorder in an affected family member and/or to the risk recurrence of that disorder.
By convention, genetic counselling is offered by trained Genetic counsellors in most genetic programs. In our country there is paucity of Genetic counsellor’s courses with resultant shortage. Hence the responsibility is shared by the attending clinicians, nurses, social workers.
In view of fragmentation of medical care into various sub-specialities, patient/family members receive confusing & at times clashing opinions with no one seemingly in charge. A multi-speciality combined counselling approach is better! Properly trained genetic counsellor can act as the mouth piece and intermediary between service providers and patient and family.
Aetiology of genetic, congenital defects is very varied and confusing, major causes include,
Chromosomal defects (0.7-1%): 1) Numerical anomalies, 2) Gross structural anomalies
Single gene disorders (1.0%)
Multi-factorial defects (2.0-2.5%), where more than one genes are involved on more than one chromosomes.
Somatic cell genetic disorders (2.5-3.0%)
Deficiencies in the maternal diet,
Teratogenic effects of drugs, chemicals,
Ionizing radiation, ultraviolet rays,
Foetal infections by bacteria, viruses and parasites
Inborn errors of metabolism:
Disorders arising due to disturbed metabolic pathways as a result of malfunctioning of enzymes regulating them
In more than 50% of congenital defects the cause is still not clearly known. With Human Genome project well underway the situation is changing very rapidly.
It is important for the counsellor to understand the tenets of Genetic Counselling, themain points to be noted are,
Trained and dedicated personnel should offer counselling
Atmosphere of privacy & confidentiality
Sensitive to patient’s emotions, religious and ethical views
Counselling should be non-directional, non-judgmental and supportive
Encourage patient & family members to actively participate.
Give all necessary information to patient & family that is required to reach proper decisions
Indications for genetic counselling include,
Single gene disorder-known or suspected,
Chromosomal defects in patient or family,
Abnormal trait or carrier stage detected by genetic screening,
Advanced maternal/paternal age,
Exposure to teratogens,
Repeated pregnancy losses,
Unexplained infertility, in ART programs
Multiple congenital anomalies diagnosed on obstetric scan
Genetic counselling encompasses following core activities,
In this stage, all possible efforts are put in to arrive at as accurate diagnosis of the problem of the “consultand”
Reason for referral,
Thorough physical check-up,
Detailed history of patient & family (genetically targeted),
Necessary laboratory, imaging & other investigations,
Preparing pedigree charts
Counselling for the specific problem:
This is done once the probable diagnosis has been reached and includes,
Evaluation of natural history of the disorder, likely complications
Estimating the accurate recurrence risk, this can be very difficult task at times.
Measures required include,
1) incidence of the disorder in general population, 2) inheritance pattern, 3)database from other centres, 4) pedigree charting, 5) screening tests, 6) use of statistical methodologies.
Prevention of recurrence:
Prenatal diagnosis, management: important factors to be considered include, 1) availability of appropriate test, 2) reliability, specificity of test, 3) clinical & laboratory risks of the test, 4) risk to benefit ratio (both for mother & foetus), 5) availability of management options.
Assisted reproductive options like use of donor eggs, sperms, PGD
Ante-natal & postnatal management options:
These depend on the time of diagnosis, severity & natural history of the disease, maternal & foetal interests.
Antenatal surveillance, term delivery and postnatal management (in mild non-progressive disorders),
Pre-term delivery by induction or LSCS neonatal therapy (for moderately severe, progressive disorder),
Foetal therapy-medical/surgical, prior to viability, followed by near term delivery & neonatal therapy.
Medical termination of pregnancy considered in lethal chromosomal, structural anomalies where no post-natal therapy is available. The couple has to take the decision
Give support to family in coping up, taking balanced decisions & implement them,
Referral to specialised centres for further tests, obstetric & neonatal management,
Psychological support to patient, affected child & family,
Guidance about special instructions, diet advice, special medical & educational facilities, follow-up,
Securing help of voluntary agencies, special disease groups,
Planning for future pregnancies.
Setting up well designed Genetic Counsellor’s training courses all over the country as well as creating job opportunities for them is the need of the hour. Multi-speciality approach for counselling & management is essential to give seamless services to the high risk population. Obstetricians interact with patients & family before pregnancy, all through nine months hence enjoy the confidence. Hence they should be the king pin of the team and should be well versed with all aspects of prenatal diagnosis.
Dr Sharad Gogate,
Surlata Hospital & Foetal Medicine Consultancy Services.