for students

1. Genetic Heterogeneity
Arslan Ahmed
Ateeqa Aslam
M. Zeeshan Akam

2. Outlines
• What is genetic heterogeneity
• Types of genetic heterogeneity
• Locus heterogeneity
• Examples of Locus heterogeneity
• Allelic heterogeneity
• Examples of Allelic heterogeneity
•

3. Genetic heterogeneity
• It occurs through the production of single or similar phenotypes
through different genetic mechanisms.
• Non-Mendelian genetics
• Phenotypes do not follow Mendel’s laws

4. Types
• Locus heterogeneity
• Allelic heterogeneity

5. Locus heterogeneity
• Also called genetic heterogeneity
• Genetic heterogeneity can be defined as mutations at two or more
genetic loci that produce the same or similar phenotypes

6. Examples:
• Ehlers–Danlos syndrome
A disease of the connective tissue, are known to result from alterations
at multiple genes inherited with autosomal-dominant, autosomal-
recessive, and X-linked-recessive patterns of inheritance.
• methylmalonic acidemia

7. Allelic heterogeneity
• It is the phenomenon in which different mutations at the same locus
cause the same phenotype.
• Mutated alleles expressing allelic heterogeneity can be classified as
adaptive or disadaptive. These mutations can occur in the germ line
cells, somatic cells, or in the mitochondrial.

8. Examples
• Alkaptonuria
• Albinism
• Achondroplasia
• Phenylketonuria