Genetic Newborn Screening for Cystinosis and Primary Hyperoxaluria

In Germany parents of newborns are offered newborn screening (NBS) for 17 congenital diseases as a standard benefit of statutory health insurance. NBS in Germany is voluntary. Cystinosis and hyperoxaluria are very rare diseases. They are inherited autosomal-recessively. Neither disease can be detected by the methods established in routine NBS. However, common genetic mutations are known for both diseases. The aim of the study is to provide a scientific basis for molecular genetic NBS for cystinosis and primary hyperoxaluria (PH). Specifically, the study will investigate whether the inclusion of these diseases into general NBS should be recommended. By observing the identified infants in comparison to patients symptomatically diagnosed outside of the pilot project, it will be determined whether and to what extent early diagnosis and therapy lead to a more favorable prognosis. The screening laboratory Hannover, Germany is involved in the project. Hospitals that send their dry blood spot cards for routine NBS to Hannover are offered participation in the project. Parents who want to participate receive an additional information sheet. A parent and the attending physician sign the information sheet as documentation of informed consent, which allows data transfer and patient referral to a specialist in case of a positive result. Molecular genetic screening in the pilot project is performed from the same dry blood spot card used for routine NBS. In both diseases, testing is performed for 2 known mutations: In cystinosis for the 2 mutations most common in Germany, and in PH for the most common mutation in infantile hyperoxaluria (PH1) and in Europe (PH3). Normal findings are not communicated to the parents, which may contact the laboratory to ask for them. Parents of newborns with two mutations in the cystinosis gene are immediately informed about the disease by a physician. Further diagnostics to confirm the disease are organized close to home. In contrast, parents of newborns with only one mutation in one of the two hyperoxaluria genes are informed. They are asked to send spot urines of the newborn to the hyperoxaluria center. Only if these are abnormal, further evaluation will be performed. The study started on 15.03.2022. The aim is to screen 200,000 newborns until 2025. If the benefit of early diagnosis and therapy can be shown, an application for inclusion of a NBS for these two diseases in the routine NBS program will be submitted to the German government.