Question

What is pedigree analysis? Suggest how such an analysis, can be useful.

Answer 1

A pedigree is a record of the inheritance of specific genetic features for two or more generations, shown as a family tree. The pedigree analysis examines a pedigree to determine the transmission of a particular trait and the probability of that trait being absent or present in a homozygous or heterozygous state in a given individual. Pedigree analysis is beneficial for the following:

1. It is beneficial for genetic counsellors to advise prospective couples of the likelihood of having children with genetic disorders such as haemophilia, colour blindness, alkaptonuria, phenylketonuria, thalassemia, sickle cell anaemia (recessive traits), brachydactyly, and syndactyly (dominant traits).
2. Pedigree analysis shows that Mendel's ideas apply to human genetics, with certain alterations discovered later, such as quantitative inheritance, sex-linked traits, and other links.
3. It can suggest the genesis of a characteristic in forebears; for example, haemophilia appeared in Queen Victoria and spread throughout Europe's royal dynasties through marriage.
4. It is helpful to understand the probability of a recessive allele causing a condition in the progeny, such as thalassemia, muscular dystrophy, or haemophilia.
5. It can suggest the potential harm that a marriage between close relatives could cause.
6. It can assist in determining whether a genetic condition is caused by a recessive or dominant gene.
7. In certain situations, it may be useful to identify the genotypes of unborn kids.