Genetic consultation (Consultation and genetic counseling in obstetrical pathology)

Some time ago, genetics was considered an over-specialised branch of the basic medicine, having insignificant applications into the practice. However, this attitude has considerably changed due to the progress made in this area concerning mainly the significance of the paraclinical diagnosis, as well as to the therapeutic possibilities of development allowing the prophylaxy and the treatment of several genetic diseases. Practically, the only method for the early diagnosis and the prevention of the genetic diseases occurrence in the family and the population is represented by the genetic counseling.
When should the consultation and the genetic counseling be given?
Before conception: infertility or investigated sterility of probable genetic cause;
– Family history of genetic illness or congenital malformation;
– Genitors of a child with a genetic affection, congenital malformation or chromosomal abnormality; the spouses are consanguineous; Antenatal, the genetic consultation is given under the before mentioned circumstances and in the following situations as well:
– Some chromosomal abnormalities detection in the fetal karyotype;
– Ultrasound detection of some abnormalities;
– The pregnant woman was exposed to agents with possible teratogenic effects (infections, drugs, radiation), either during the conceptual period or afterwards, during the pregnancy;
Postnatal, the genetic advice is required in the following situations:
– The results of neonatal screening tests show the existence of a genetic illness;
– Detection of chromosomal abnormalities, somatic dysmorphia or congenital malformations;
still-born child.
The diseases of genetic etiology are classified into three categories:
1. Chromosomal diseases represent a child’s birth with a chromosomal abnormality, either numeric or structural: trisomy 21, trisomy 18, trisomy 13 or gonosomal trisomy (47, XXY or 47, XXXY).
2. Monogenic diseases occur as a result of a single genetic mutation. They are hereditary, being transmitted according to Mendel’s laws of the hereditary features transmission (also named the Mendelian diseases). There are known three types of transmission of the monogenic diseases that have the following characteristics: – Autosomal-dominant (ex: Huntington’s disease, Marfan’s disease, polycystic kidney, retinoblastoma); autosomal-recessive (ex: thalassemia, cystic fibrosis;- sex-linked dominant or recessive; X-linked dominant (rachitis).
3. Polygenic diseases (multi-factorial) are the result of interaction between more genes predisposing to the illness development. The majority of genetic diseases is of this type: HTA, diabetes, schizophrenia. The transmission of these diseases eludes the Mendel’s laws.