Galactosemia is a metabolic disorder characterized by the inability to metabolize the sugar galactose. People with galactosemia suffer from liver, kidney, and brain damage among other symptoms. A gene mutation underlying galactosemia was identified by sequencing the genome of a person with galactosemia. What additional evidence would support the hypothesis that the mutation in the candidate gene causes the disease

Genetic mapping for unequivocal identification of the potentially causative mutation  

Explanation:

Galactosemia is a genetic disorder caused by mutations in the Galactose-1-phosphate uridylyltransferase (GALT) gene, which encodes an enzyme involved in the metabolism of galactose. Gene mapping is a technique widely used in genetics to identify the position of one locus a chromosome by using molecular markers to estimate genetic distances. Genetic mapping provides useful evidence in order to identify when a disease that is transmitted from parent to offspring can be associated with one or more genes and then determine which gene/s is/are responsible for this condition.