Introduction to Metabolic diseases

Human beings are subjected to a variety of metabolic diseases, as we are a complex set of structures that function through quite varied and intertwined metabolic processes. Most metabolic diseases have genetic basis while some are acquired in life or need the complex interplay between nature and nurture for their existence. Genetic diseases either follow a single gene disorder or a polygenic basis with multifactorial disorders. 

A. Metabolic diseases with a single gene disorder 

These metabolic diseases follow a Mendelian type of inheritance i.e. they follow an autosomal dominant disorder (e.g., Familial hypercholesterolemia, Acute intermittent porphyria); an autosomal recessive disorder (e.g. Phenylketonuria, Galactosemia, Glycogen storage diseases); and x-linked recessive disorders (e.g. Phosphorylase kinase deficiency, GSD). These are all rare Biochemical genetic  diseases and they are beyond the scope of this lecture note. 

 B. Metabolic disease with a polygenic disorder

These metabolic diseases have multifactorial modes of inheritance.

They are caused by the additive effects of two or more genes of small effect but conditioned by environmental, non-genetic influences. Example in these groups of metabolic diseases includes Diabetes mellitus and Gout.  

References

Bezabeh ,M. ; Tesfaye,A.; Ergicho, B.; Erke, M.; Mengistu, S. and Bedane,A.; Desta, A.(2004). General Pathology. Jimma University, Gondar University Haramaya University, Dedub University.