a) Interpretation of Results. Although the majority of infants affected by amino acid, organic acid and fatty acid oxidation disorders will be identified by this screening, due to genetic variabilities and variations in health status, specimen quality, and timing of specimen collection, not all infants affected by the disorder may be identified. As with any laboratory test, false positive and false negative results are possible. Newborn screening test results are insufficient information on which to base diagnosis or treatment.

1. 1) The patient metabolite distribution patterns shall be compared to normal populations. Pattern analysis, and internal metabolite ratios relative to normal populations, shall be calculated using accepted statistical techniques (for example, as described by the Association of Public Health Laboratories, see Section 660.20).
2. 2) When blood levels or ratios are found to be abnormal, indicating the possibility of a metabolic condition harmful to the infant, the Department will recommend a repeat newborn screening test or referral of the newborn to a designated medical specialist for appropriate definitive testing and diagnostic studies.

b) Designation of Medical Specialist. In addition to the minimum qualifications set out in Section 661.230, the medical specialist shall possess the following:

1. 1) For all disorders of amino acid, and organic acid metabolism, medical specialists designated by the Department to follow-up on a screen positive result shall possess certification by the American Board of Medical Genetics and Genomics in Clinical Biochemical Genetics, Medical Biochemical Genetics or certification by the American Board of Medical Genetics and Genomics in Clinical Genetics with at least one year of experience post-training in the diagnosis and treatment of amino acid and organic acid disorders. The disorders of amino acid and organic acid metabolism medical specialist shall have the capacity to provide a multidisciplinary approach to care, including the availability on site of specially trained metabolic dietitians and a biochemical genetics laboratory; for citrullinemia and argininosuccinic aciduria, medical specialists should have on-site availability of required medical therapies, such as hemodialysis, that are necessary for the treatment of patients with these disorders.
2. 2) For fatty acid oxidation disorders, medical specialists designated by the department to follow-up on a screen positive result shall possess certification by the American Board of Medical Genetics and Genomics in Clinical Biochemical Genetics, Medical Biochemical Genetics or certification by the American Board of Medical Genetics and Genomics in Clinical Genetics with at least one year of experience post-training in the diagnosis and treatment of fatty acid oxidation disorders. Fatty acid oxidation disorders medical specialists should have the capacity to provide a multidisciplinary approach to care, including the availability on site of specially trained metabolic dietitians.