Galactosemia is a rare genetic

Genetics

Genetics , a discipline of biology, is the science of genes, heredity, and variation in living organisms....

 metabolic

Metabolism

Metabolism is the set of chemical reactions that happen in the cells of living organisms to sustain life. These processes allow organisms to grow and reproduce, maintain their structures, and respond to their environments. Metabolism is usually divided into two categories...

 disorder

Disease

A disease is an abnormal condition affecting the body of an organism. It is often construed to be a medical condition associated with specific symptoms and signs. It may be caused by external factors, such as infectious disease, or it may be caused by internal dysfunctions, such as autoimmune...

 that affects an individual's ability to metabolize the sugar galactose

Galactose

Galactose , sometimes abbreviated Gal, is a type of sugar that is less sweet than glucose. It is a C-4 epimer of glucose....

 properly. Although the sugar lactose can metabolize to galactose, galactosemia is not related to and should not be confused with lactose intolerance

Lactose intolerance

Lactose intolerance, also called lactase deficiency or hypolactasia, is the inability to digest and metabolize lactose, a sugar found in milk...

. Galactosemia follows an autosomal recessive mode of inheritance that confers a deficiency in an enzyme responsible for adequate galactose degradation.

Goppert first described the disease in 1917, with its cause as a defect in galactose metabolism being identified by a group led by Herman Kalckar

Herman Kalckar

Herman Moritz Kalckar was a Danish biochemist who pioneered the study of cellular respiration. Trained as a medical doctor at the University of Copenhagen, Kalckar then conducted research for his Ph. D. in Ejnar Lundsgaard's physiology laboratory, work which helped establish a fundamental...

 in 1956.

Its incidence is about 1 per 60,000 births for Caucasians.