IllnessGalaktosemia, differential diagnosis

NGS +

The symptoms of galactosemia are due to insufficient breakdown of galactose from food for generating energy. Three different types are caused by mutations in three specific genes, and they affect different enzymes. Classic galactosemia (type I) represents the most common and severe form, requiring immediately low-galactose diets to prevent life-threatening complications. Affected infants typically develop feeding difficulties, lethargy, lack of weight gain and failure to thrive, jaundice, liver damage, hemorrhage, sepsis, shock, cataracts, speech disorders and mental retardation. Galactosemia type II (galactokinase deficiency) mainly causes cataract; type III (galactose epimerase deficiency) causes mild to severe symptoms with cataract, delayed growth and development, intellectual deficit as well as liver and kidney problems. Various mutations in the GALT gene result in classic TYPE I galactosemia, but with varying severity. Type II results from mutations in the GALK1 gene, while mutations in the GALE gene underlie type III. Galactosemia is inherited in an autosomal recessive manner. The molecular genetic yield exceeds 95% by far. Thus, the respective DNA tests confirm virtually always the clinical diagnosis, especially when also the other differential diagnostic relevant genes are included.

Reference: https://www.ncbi.nlm.nih.gov/books/NBK1518/

• Alias: GALT Deficiency
• Alias: Galactose-1-Phosphate Uridylyltranserase Deficiency
• Alias: Galactosemia I
• Allelic: Deafness, congenital heart defects + posterior embryotoxon (JAG1)
• Allelic: Hajdu-Cheney syndrome (NOTCH2)
• Allelic: Tetralogy of Fallot (JAG1)
• Alagille syndrome 1 (JAG1)
• Alagille syndrome 2 (NOTCH2)
• Cholestasis, benign recurrent intrahepatic (ATP8B1)
• Cholestasis, intrahepatic, of pregnancy, 1 (ATP8B1)
• Cholestasis, progressive familial intrahepatic 1 (ATP8B1)
• Citrullinemia, adult-onset type II (SLC25A13)
• Citrullinemia, type II, neonatal-onset (SLC25A13)
• Fructose intolerance, hereditary (ALDOB)
• Galactokinase deficiency with cataracts, Galactosemia II (GALK1)
• Galactose epimerase deficiency, Galactosemia III (GALE)
• Galactosemia (GALT)
• Galactosemia IV (GALM)
• Niemann-Pick disease, type C1 + D (NPC1)
• Niemann-Pick disease, type C2 (NPC2)
• Tyrosinemia, type I (FAH)