This is a rare genetic condition that occurs when the body is not able to convert the galactose, the sugar from the milk to glucose. This develops as the result of a deficiency in an enzyme known as galactose-1 phosphate uridyl transferase (GALT) which is necessary for the sugar metabolism. The early diagnosis can prevent the liver failure and even death among the newborn infants who require immediate treatment soon after the birth. There are three types of this condition that are identified as the classic galactosemia (type I), galactokinase deficiency (type II) and epimerase deficiency (type III).
Causes
There are three genetic mutations that are identified to cause the three types of this condition. The mutation in the gene GALT causes the type I, GALK1 gene causes type II and the mutation in the GALE gene results in type III. All these three genes are essential for the production of enzymes that are required for the metabolizing of the galactose that is converted to sugar and other materials that can be stored as energy by the body. With the genetic mutation, there is decreased level of these essential enzymes which results in the accumulation of various compounds that becomes toxic to the body. This condition is inherited in an autosomal recessive pattern meaning both the copies of the gene in each cell are defective.
Symptoms
The symptoms develop as the result of the body’s inability to use galactose for the energy required. The type I is the common and the most severe form of galactosemia. The early diagnosis soon after the birth is important to prevent the life-threatening complications that can develop within a few days. The symptoms include lacking energy, feeding problems, failure to grow or gain weight at the expected rate, jaundice and liver damage. Additional complications can include bacterial infections, cataract, delayed development, intellectual disability and problems with speech. Individuals with the type II often exhibit less medical problems and fewer complications. The type III may exhibit intellectual disability, kidney disease, liver problems, delayed growth and development.
Diagnosis
This condition is identified when the galactose-1-phosphate is high in the red blood cells and the activity of the enzyme GALT is reduced. The genetic testing is also possible that identifies the genetic mutation that is responsible for causing this condition.
Treatment
The treatment is focused on reducing the intake of diet that contains galactose. Children with this condition can have a proper physical development when a diet is monitored. The use of antibiotics may be necessary in the case of infections. Depending on the psychological development of the children, speech therapy, supportive measures and additional new learning skills may be required. In some of the cases, genetic counseling may be beneficial for some of the affected children’s families.
References
https://ghr.nlm.nih.gov/condition/galactosemia#inheritance
http://www.galactosemia.org/understanding-galactosemia/
https://rarediseases.org/rare-diseases/galactosemia/
