Medical Genetics - V. M. Zaporozhan 2005

Prevention of Hereditary Diseases
Types of Prevention of Hereditary Pathology

There are two main approaches to the Prevention of Hereditary Disorders: family-based prevention (predicting and preventing new cases within a specific family) and population-based prevention (relying on specialized screening programs for certain conditions in newborns or during Pregnancy).

All preventive measures can be divided into two groups: 1) primary prevention — measures aimed at preventing the conception of an affected child; 2) secondary prevention — measures aimed at preventing the birth of an affected child or The Development of a pathological phenotype. Secondary prevention is carried out during pregnancy or in the postnatal period (prenatal Diagnostics, correction of pathological genotype manifestations in the antenatal and postnatal periods, etc.). Sometimes phenotype correction is classified as tertiary prevention.

Morphology/3.html">MAIN DIRECTIONS OF PRIMARY PREVENTION

1. Environmental protection. This is achieved through strict monitoring of mutagen and teratogen levels in the environment and their elimination based on hygienic standardization principles.

2. Structure/175.html">Implementation of Population Genetic monitoring programs. Genetic monitoring refers to the systematic tracking of the dynamics of the frequency and spectrum of hereditary disorders, as well as the level of environmental pollution by mutagens.

3. Family planning requires compliance with several conditions:

— choosing the optimal age for childbearing (21–35 years for women and 21–40 years for men). Advanced maternal age (both very young mothers and those over 35) is associated with a high risk of chromosomal abnormalities, while paternal age is linked to the risk of new Gene Mutations. Planning for 2–3 children during this age window is sufficient for most families;

— avoiding childbearing in cases of a high risk of hereditary pathology (when reliable Methods of prenatal Diagnosis, Treatment, adaptation, and rehabilitation for affected individuals are unavailable);

— avoiding consanguineous marriages. For unrelated parents, the overall risk of having a child with Hereditary and Congenital disorders is 5.5%. If the parents are first cousins, the genetic risk doubles. Consanguineous marriages significantly increase the risk of children born with recessive diseases.

4. Medical and Genetic Counseling for families that already have an affected child (retrospective) or prior to childbearing (prospective).

5. Preconceptional Prevention of Hereditary diseases — creating optimal conditions for gametogenesis, Fertilization, and the Cytology/cytology/16.html">Early stages of embryonic development. Broad promotion of preconceptional prevention elements among the general population. This includes educational work to foster a healthy lifestyle and eliminate harmful habits (alcohol consumption, drug use, smoking), as well as A balanced diet for both partners 2–3 months prior to planned conception and for women During the first 3 months of pregnancy:

— intake of multivitamins with microelements (iodine, manganese, zinc, etc.);

— daily intake of 400 mcg of Folic acid (significantly reducing the incidence of neural tube defects);

— fortification of food products with iodine in endemic areas to prevent thyroid dysfunction;

— application of a specialized radioprotective diet in areas contaminated with radionuclides.

6. Integration of Diagnostic methods for hereditary disorders into modern reproductive technologies (Genetic Testing of sperm Donors used for Artificial Insemination, Preimplantation Genetic Diagnosis during In vitro fertilization, etc.).

MAIN DIRECTIONS OF SECONDARY PREVENTION

1. Prenatal diagnosis.

2. Termination of pregnancy in cases where a hereditary pathology leading to severe disability or early death is diagnosed in the fetus, and no effective treatments exist. Pregnancy termination is performed only within established gestational limits and with the woman's informed consent.

3. In utero treatment of certain Hereditary diseases and developmental defects during pregnancy.

4. Mass Newborn Screening for the preclinical diagnosis of hereditary diseases for which preventive treatments have been developed (phenylketonuria, hypothyroidism, etc.). Preventive treatment of affected individuals.

5. Identification of heterozygous carriers of recessive mutant genes.

6. Detection of late-onset disease genes and predisposition genes for multifactorial disorders, along with the prevention of these pathologies in gene carriers.

7. In the future — the creation of a Genetic Passport for newborns.