Medical Genetics - V. M. Zaporozhan 2005

Classification, general characteristics, and symptomatology of hereditary diseases. General clinical diagnostics.
General principles of clinical diagnostics of hereditary diseases
Peculiarities of anamnesis collection

The patient's examination is carried out According to the standard Procedure.

When collecting personal data and medical history, attention should be paid to the following:

1. Full name of the parents. For the mother, her maiden name must be indicated. A matching surname of the father and the mother's maiden name may help identify a consanguineous marriage. Such marriages increase the likelihood of children born with Autosomal Recessive Disorders.

2. Age of the proband (indicating the proband's date of birth) and the age of the parents at the time of the proband's birth. As the age of both parents increases, the risk of having children with certain Hereditary diseases rises. For instance, advanced paternal age increases the probability of new dominant Gene Mutations (such as Achondroplasia and neurofibromatosis), whereas maternal age over 35 indicates an elevated likelihood of giving birth to a child with chromosomal abnormalities.

3. Nationality of the parents (Table 3.1). Certain hereditary diseases occur predominantly in individuals of a specific ethnicity (or residents of a particular geographic region).

4. Place of residence of the family and maternal/paternal ancestors. If, over several generations, ancestors on both sides lived in the same small settlement, the probability of consanguineous marriages is high. Furthermore, information on the family's place of residence helps rule out endemic diseases and account for potential environmental factors.

Table 3.1. Hereditary diseases with a higher prevalence in individuals of specific ethnicities

5. Occupation. Attention is paid to potential exposure to mutagenic and teratogenic factors; for the same reason, it is necessary to determine the branch of military service in which the father served.

6. Maternal chronic illnesses. Attention is drawn to cardiovascular and respiratory diseases, Epilepsy, diabetes, phenylketonuria, etc. The developing fetus can be adversely affected by both the maternal condition itself (Fetal Hypoxia in cardiovascular diseases, diabetic embryofetopathy, phenylpyruvic embryofetopathy) and medications used for its Treatment (for instance, anticonvulsants prescribed for epilepsy are known teratogens).

7. Adverse obstetric history. A history of spontaneous abortions, missed miscarriages, and stillbirths may indicate the presence of a balanced chromosomal mutation or other Genetic Disorders in either the father or the mother.

8. Significant family history. The presence of children with hereditary pathology, developmental malformations, or early childhood deaths of unknown cause in the family or among close relatives may indicate the inheritance of pathological genes or balanced chromosomal rearrangements within the family.

9. Complicated course of the Pregnancy that resulted in the birth of the proband:

a) threatened Miscarriage is observed in fetal chromosomal and certain monogenic syndromes;

b) intrauterine growth restriction, determined through a series of ultrasonographic measurements. It is frequently observed in fetal chromosomal syndromes, monogenic syndromes, intrauterine infections (cytomegalia, congenital rubella, Syphilis), radiation injury, Multiple pregnancy, and fetal pancreatic aplasia. Intrauterine growth restriction should be differentiated from hereditary dwarfism syndromes;

c) oligohydramnios may indicate fetal Urinary Tract disorders accompanied by decreased normal urine production. Oligohydramnios itself acts as a teratogenic factor;

d) polyhydramnios is observed in fetal gastrointestinal malformations involving impaired swallowing function;

e) decreased fetal mobility is characteristic of Arthrogryposis and Down syndrome.