Newborn Screening TestsPhenylketonuria (PKU). PKU is an inherited disease in which the body can't metabolize a protein called phenylalanine. ... Congenital hypothyroidism. ... Galactosemia. ... Sickle cell disease. ... Maple syrup urine disease. ... Homocystinuria. ... Biotinidase deficiency. ... Congenital adrenal hyperplasia.