Variants in COL4A1 and COL4A2 are associated with a multisystem disorder characterized by prominent neurologic involvement that includes intracranial hemorrhages, white matter injury, neurodevelopmental impairment, and epilepsy. The phenotypic spectrum, however, is broad, and disease subgroups have not been robustly identified. The objective of this study was to distinguish pediatric subgroups based on age at symptom onset.
Porcari et al. (Mon,) studied this question.