Answer to Question 1
F
Answer to Question 2
Amino acid disorders include conditions affecting the metabolism of a single amino acid, such as PKU or isovaleric acidemia (IVA), as well as disorders involving multiple amino acids, such as MSUD. Several of these conditions were discovered less than 50 years ago. Incidence of these disorders can vary significantly, with the most common amino acid disorder, PKU, having an incidence of 1 in 15,000 births. The rarer disorders such as isovaleric acidemia or homocystinuria, however, have incidences of less than 1 in 100,000 births. Incidence of these disorders can vary based on ethnicity. Those populations that tend to be more homogenous have been found to have higher rates of certain disorders. For example, MSUD has been detected at an incidence of 1 in 290,000 births in state screening programs. In the Mennonite Community, a homogeneous group in Pennsylvania, there is a much higher prevalence for this condition at 1 in every 790 births.
