MedGen

Autosomal dominant deafness-83 (DFNA83) is characterized by the onset of progressive sensorineural hearing loss at an average age of 24 years. A notable finding is a normal distortion product otoacoustic emissions (DPOAE) test, implicating dysfunction of spiral ganglia neurons rather than outer hair cells as a disease mechanism (Cui et al., 2020). [from OMIM]

Periventricular nodular heterotopia-9 (PVNH9) is an autosomal dominant neurologic disorder characterized as a malformation of cortical development. Anterior predominant PVNH, thin corpus callosum, and decreased white matter volume are found on brain imaging, but the clinical effects are variable. Most patients have impaired intellectual development and cognitive defects associated with low IQ (range 50 to 80), learning disabilities, and behavior abnormalities. Some patients develop seizures that tend to have a focal origin. However, some mutation carriers may be less severely affected with borderline or even normal IQ, suggesting incomplete penetrance of the phenotype (summary by Heinzen et al., 2018, Walters et al., 2018). For a discussion of genetic heterogeneity of periventricular nodular heterotopia, see 300049. [from OMIM]