RESUMEN
Galactosemia is a rare autosomal recessive disorder caused by the deficiency of galactose-1-phosphate uridyltransferase (GALT) enzyme activity. Classic galactosemia (G/G) is due to severe GALT deficiency in the presence of a GALT gene mutation, whereas Duarte variant (D/D) has 50% of normal GALT activity and benign clinical course. The D2 allele of Duarte variant is linked to a promoter deletion 5' to the translation start site (-119 to -116 delGTCA) in addition to N314D. So, Duarte variant/classical galactosemia (D/G) compound heterozygotes have relatively mild clinical manifestation than classical galactosemia and can be differentiated from classical galactosemia or Duarte variant by mutational analysis. We report a case of D/G galactosemia compound heterozygote proven by the reduction of GALT enzyme activity in erythrocytes and mutation analysis of GALT gene, which revealed N314D polymorphism and -119 to -116 delGTCA.