1. (a) Identification. A Spinal Muscular Atrophy (SMA) newborn screening test system is a prescription device intended to detect homozygous deletion of exon 7 or other similar mutations in the SMN1 (Survival Motor Neuron 1) gene of DNA obtained from dried blood spot specimens on filter paper using a polymerase chain reaction-based test as an aid in screening newborns for SMA. Presumptive positive results are intended to be followed up by diagnostic confirmatory testing.

2. (b) Classification. Class II (special controls). The special controls for this device are:

   1. (1) Design verification and validation must include the following:

      1. (i) A detailed device description, including all device parts (e.g., instruments and associated user manuals, device software, reagents, calibrators, controls, and consumables) and their use within the testing procedure.
      2. (ii) A detailed explanation of the technology, method(s) of data processing from signal acquisition to result assignment, and pre-specified cut-offs used to interpret the data and generate results and sample reports.
      3. (iii) A description of appropriate internal and external controls that are recommended or provided. The description must identify those control elements that are incorporated into the testing procedure.
      4. (iv) Detailed specifications for the filter paper to be used as part of the device, which must be appropriately labeled for in vitro diagnostic use. Specifications must include punch size and address any properties of the filter paper that may interfere with obtaining test results.

      5. (v) Detailed documentation of the following analytical and clinical studies, including the study protocols containing descriptions of the test methods, prescribed methods of data analysis and acceptance criteria, final study reports, and data line listings:

         1. (A) A study demonstrating the clinical performance of the device using well characterized prospectively or retrospectively obtained clinical specimens from the intended use population and include homozygous and heterozygous specimens of sufficient number to be determined to be acceptable to FDA. Confirmed positive specimens must have a diagnosis based on confirmatory diagnostic methods. The confirmed positives must include samples from SMA types 1-4. Additionally, samples with SMN2 (Survival Motor Neuron 2) copy number ranging to 4 must be evaluated to determine the risk of false negative (unaffected) results due to assay cross reactivity with the SMN2 gene. A description of the sample collection strategy and accountability must be included. Specimens used in the study must be from patients other than those used to design the test, and validation testing must be based on a pre-specified clinical decision point (i.e., cutoff to distinguish positive and negative results). Results must be summarized in a tabular format comparing interpretation of results to the reference method. Point estimates together with two-sided 95 percent confidence intervals must be provided for the positive percent agreement (sensitivity) and negative percent agreement (specificity). Data must include the retest rate, false positive rate before retest, final false positive rate, and false negative rate. Positive predictive value and negative predictive value must be provided based on published reference to prevalence in the target population.
         2. (B) A study demonstrating device accuracy in comparison to the results obtained by a reference or comparator method determined to be acceptable by FDA.
         3. (C) A study demonstrating device reproducibility generated using a minimum of three sites, of which at least two must be external sites, with at least two operators at each site using the specified extraction method(s) and protocol. The evaluation must include multiple runs, days, different instruments, and different reagent lots. The study must include heterozygous deleted, homozygous deleted, and unaffected specimens. Identical specimens from the same sample panel must be tested at each site. Results must be summarized in a tabular format and reported as standard deviation and 95 percent confidence intervals for the quantitative result and agreement for qualitative results for between-site, between-operator, between-day/run, and within-run (repeatability) for each specimen.
         4. (D) A lot-to-lot reproducibility study of each filter paper intended to be used with the test. The lot-to-lot study must include a minimum of three lots of each blood spot card that will be validated with the test and be conducted over five nonconsecutive days. The sample panel must consist of at least one positive and one negative specimen. Multiple punches must be obtained from each card for demonstration of homogeneity of the analyte across the dried blood spot. Comparability of the test performance for each filter paper must be demonstrated. Stability and storage of SMN1 DNA on each blood spot card must be demonstrated. Results of the lot-to-lot study must be summarized by providing the agreement within replicates on the assay final result for positive and negative specimens with pre-specified acceptance criteria and 95 percent confidence intervals for all data. Data must be calculated for within-lot and between-lot reproducibility. Data demonstrating the concordance between results across different filter papers must be provided. Study acceptance criteria must be provided and followed.
         5. (E) A study demonstrating device specificity, including interference, carryover/cross-contamination, and analysis of potential off-target genomic sequences, including evaluation of SMN2 amplification, to evaluate the risk of clinically false negative or false positive results.
         6. (F) Studies performed to support the stability of samples using the indicated specimen collection method(s) under various storage times, temperatures, and freeze-thaw conditions, as applicable.
         7. (G) Studies performed to demonstrate on-board and in-use reagent stability, including the test method(s), data analysis plans, acceptance criteria, final study reports, and data line listings. Such documentation must include studies to demonstrate reagent shelf-life for the assay kit, including study protocols containing descriptions of the test method(s), data analysis plans, and acceptance criteria.
         8. (H) Studies performed to evaluate the risk of false positive and false negative results (e.g., validation of the cycle thresholds or other metric, as applicable, used to define the assay reportable range when assessing a range of DNA input, equivalency of different filter paper, and the limit of blank, when determined appropriate by FDA).
         9. (I) A shipping stability study, separate from the study described in paragraph (b)(1)(v)(G) of this section, must be performed that demonstrates acceptable stability of the parts that comprise the kit.
      6. (vi) A detailed description of the impacts of any software, including software applications and hardware-based devices that incorporate software, on the device's functions.
      7. (vii) Identification of all risk mitigation elements used by the device, including a detailed description of all additional procedures, methods, and practices incorporated into the instructions for use that mitigate risks associated with using the device.

   2. (2) The labeling required under § 809.10(b) of this chapter must include:

      1. (i) An intended use statement that includes:

         1. (A) A detailed description of the target(s) the device detects; and
         2. (B) The clinical indications appropriate for test use.

      2. (ii) Prominent and conspicuous limiting statements clearly explaining:

         1. (A) This test is not intended to screen for SMA subtypes other than those specifically stated in the intended use, nor is it intended for carrier screening, as a stand-alone diagnostic test, or for determining eligibility for therapeutic products.
         2. (B) Test results are intended to be used in conjunction with other clinical and diagnostic findings, consistent with professional standards of practice, including confirmation of presumptive positive results by diagnostic confirmatory testing and clinical evaluation, as appropriate.
      3. (iii) Description of the device information required under paragraphs (b)(1)(i) through (iv) of this section.
      4. (iv) A summary of the results of the studies required under paragraphs (b)(1)(v)(A) through (G) of this section.

[91 FR 35386, June 11, 2026]