Medical Genetics - V. M. Zaporozhan 2005

Clinical-Genealogical Method
Significance of the Method. Principles of Pedigree Construction
Collection of Genealogical Anamnesis

The collection of genealogical information (Stage I) begins with the proband. The proband is the affected individual or carrier of a pathological trait. Inquiries should be made about the proband's sibs (brothers and sisters), parents, maternal relatives, and paternal relatives. It is essential to gather information regarding any illnesses, with special attention given to spontaneous abortions, stillbirths, and infant deaths. The age at death and the cause of death must also be specified.

Information about sibs (and other relatives) should be collected in birth order.

It is important to determine whether consanguineous marriage exists within the family, as close relatives are more likely to be heterozygous for the same pathological Gene.

When taking a genealogical history, the following questions should be answered:

1. What was the birth order of the proband in the family?

2. How many total pregnancies has the proband's mother had?

3. How did the first Pregnancy end? The second, and so on?

4. What illnesses did the sibs have?

5. What were the causes and ages of death for the sibs?

6. At what gestational age and for what reasons were pregnancies terminated?

Questions concerning the mother's family:

1. What was the mother's birth order in her family?

2. Do the mother's sisters and brothers have children?

3. What is the number of children in birth order and their health status?

4. What are the causes and ages of death of the maternal relatives?

The same information must be obtained regarding the maternal grandmother, grandfather, and their relatives.

Next, proceed to collect analogous information about the father and all of his relatives.

It is desirable to examine the proband's close relatives in person. If this is not possible, the phenotypes of relatives should be analyzed using family photographs. In some cases, it is necessary to obtain archival data, autopsy reports of deceased family members, or review medical records. All of this is required to determine the mode of Inheritance of the trait within the family.