Classic<unk> mia has an autosomal recessive pattern of inheritance. All forms of<unk> mia are inherited in an autosomal recessive manner, meaning individuals affected with classic<unk> mia must have inherited a mutated copy of the GALT gene from both parents. Each child from two carrier parents would have a 25% chance of being affected, a 50% chance of being a carrier, and a 25% chance of inheriting normal versions of the gene from each parent. There are several variants in the GALT gene, which have different levels of residual enzyme activity. A patient homozygous for the one of the severe mutations in the GALT gene (commonly referred to as G/G) will typically have less than 5% of the enzyme activity expected in an unaffected patient. Duarte<unk> mia is caused by mutations that produce an unstable form of the GALT enzyme, with reduced promoter expression. Patients who are homozygous for Duarte mutations (D/D) will have reduced levels of enzyme activity compared to normal controls, but can often maintain a normal diet. Compound heterozygotes (D/G) will often be detected by newborn screening and treatment is based on the extent of residual enzyme activity.
Galactose-1-phosphate uridylyltransferase deficiency
Arginine:glycine amidinotransferase deficiency
Ribose-5-phosphate isomerase deficiency
Malonyl-CoA decarboxylase deficiency
Ornithine aminotransferase deficiency
Galactose epimerase deficiency
Guanidinoacetate methyltransferase deficiency
Adenine phosphoribosyltransferase deficiency