|In 2016, 6 girls were identified with variants in the HNRNPH2 gene in a study by Dr. Jennifer Bain. She found that each individual had developmental delay or intellectual disability, as well as atypical muscle tone. Many of the girls also experienced seizures and conditions such as anxiety and autism spectrum disorder (ASD). They discovered variants in HNRNPH2 also seemed to affect other organ systems in the body aside from the brain. For instance, patients with mutations in HNRNPH2 also had problems with growth, gastroesophageal reflux disorder, scoliosis and other skeletal problems, heart problems, and atypical facial features.
Since the initial 6 individuals were identified, 36 additional cases of individuals with variants in HNRNPH2 have been identified. The majority of individuals affected are girls, although variants have been confirmed in 4 boys. Dr. Bain’s research has employed the use of a prospective testing battery where assessments are remotely administered to test for various neurologic, behavioral, psychiatric, developmental, and social factors, as well as gathered information from former genetic reports and medical records. Additionally, motor assessments were conducted, as well as electroencephalography, at the 2018 HNRNPH2 family meeting. These testing measures revealed similar clinical symptoms to that of the original group, including atypical facial features, neurologic abnormalities, atypical gait, and abnormal muscle tone. The expanded group reported fewer seizures than the original group. A predominance of anxiety was found in the expanded group.