What is the gene? What protein is produced from this gene?
The gene is GALT. GALT produces galactose-1-phosphate uridylyltransferase. This enzyme enables the body to process a simple sugar called galactose, which is present in many foods.
How/When was the Disease discovered?
Galactosemia was first discovered in 1908 by Von Ruess in a 1908 publication entitled, "Sugar Excretion in Infancy". In this publication, he reported on a breast-fed infant with failure to thrive and enlargement of the liver and spleen. This infant failed to metabolize galactose when milk products were removed from the diet. He was generally accepted as the first person to report on a patient with Galactosemia. Leloir worked out the metabolic pathway and the process of sugar-nucleotides and won the Nobel prize in Chemistry in 1970 for his work.
What is the incidence of Galactosemia?
Classic Galactosemia occurs in 1 in 30,000 to 60,000 newborns in US. Galactosemia type II and type III are less common. Type II probably affects fewer than 1 in 100,000 newborns and type III appears to be very rare.
Does the disease occur in a specific ethnicity?
Galactosemia can occur in any ethnicity, but it is most common in people of the Irish descent. 1 in 24,000 Irish babies is born with this condition
What are the symptoms?
Infants with Galactosemia show symptoms of lethargy, convulsions, irritability, vomiting, jaundice and poor weight gain. Jaundice is a medical condition that involves yellowing of the skin or whites of the eyes
Possible systems of Galactosemia
How is Galactosemia diagnosed?
100% of infants with classic Galactosemia or clinical variant Galactosemia can be detected in newborn screening programs that include testing for Galactosemia in their panel. However, infants with clinical variant Galactosemia may be missed if the program only measures blood total galactose level and not erythrocyte GALT enzyme activity.
How is Galactosemia treated?
It is treated by avoiding foods with lactose and galactose (sugars found in milk) to prevent the toxic build-up of undigested sugars. Some people may need to avoid all milk products and take calcium supplements. Doctors can recommend foods and formulas that do not contain lactose or galactose. This diet will likely need to continue through adulthood.
What is the prognosis of a person with Galactosemia?
Even if a child avoids all foods that contain galactose, a buildup of undigested sugars may still occur because the human body makes a small amount of this on its own. Some children with who receive treatment early still show delays in learning, development, speech/language, and motor skills. Without treatment, babies with Galactosemia are at risk of developing vision trouble, liver trouble, low blood sugar (called hypoglycemia), blood infections, developmental delays, and intellectual disabilities. Babies who do not receive treatment can die within their first weeks or months of life.
What is the genetic pattern of inheritance?
Galactosemia is an autosomal recessive inheritance. Parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.
What is the current research on Galactosemia?
Unexpected problems with the GALT assay posed a challenge to switch to a new assay. The aim of this study was to make an analytical and clinical evaluation of GALT assays to replace the current assay and establish new cut-off values (COVs). The manual assay from PerkinElmer and the GSP assay were compared by analyzing 626 anonymous heel prick samples. Secondly, a manual GSP method was evaluated and 2,052 samples were compared with the automated GSP assay. Finally, a clinical evaluation was performed by collecting data from 93 referred newborns. They adopted both methods in the Dutch screening laboratories. As a result of this evaluation, new COVs for GALT and TGAL have been introduced and are valid from July 2015.
“Classic Galactosemia.” Baby’s First Test, edited by Natasha Bonhomme, 2017, www.babysfirsttest.org.
Djan, Grace. Leloir. Feb. 2014. Galactosemia, allaboutgalactosemia.blogspot.com. Accessed 2 Feb. 2017.
“Galactosemia.” Genetics Home Reference, www.ghr.nlm.nih.gov. Accessed 1 Feb. 2017.
“Galactosemia.” Star-G, www.newbornscreening.info. Accessed 2 Feb. 2017.
“Growing up with Galactosemia.” Youtube, uploaded by Save Babies Through Screening Foundation, 1 Aug. 2012, www.youtube.com.
“History of Galactosemia.” Galactosemia Foundation, edited by Arthur Maltson, www.galactosemia.org. Accessed 1 Feb. 2017.
Kemper, E. A. “Establishing New Cut-Off Limits for Galactose 1-Phosphate-Uridyltransferase Deficiency for the Dutch Newborn Screening Programme.” NCBI, PubMed, www.ncbi.nlm.nih.gov. Accessed 1 Feb. 2017.
The symptoms of an infant with Galactosemia. Pediatrics ClerkShip, U of Chicago, 2013, pedclerk.bsd.uchicago.edu.