Hearing Loss
All CLPP related disorders – Sensorineural hearing loss is bilateral and severe to profound with onset pre-lingual (congenital) to early-childhood. When onset is in early childhood, hearing loss can be progressive. There is no evidence of impaired vestibular function.
Ovarian Dysfunction
Perrault syndrome – Affected females have gonadal dysfunction presenting as a spectrum of ovarian dysfunction ranging from gonadal dysgenesis presenting as primary amenorrhea (also known as primary ovarian failure) to primary ovarian insufficiency (POI) (presenting as secondary amenorrhea). Ovaries are small, streak or absent and hormone profiles indicate hypergonadotropic hypogonadism.
Neurological Features
Perrault syndrome – Members of families with CLPP-related Perrault syndrome have been reported with or without neurologic features which include; learning difficulties, developmental delay, cerebellar ataxia and motor and sensory peripheral neuropathy. There is no consistent pattern observed in the neurological features.
Other CLPP associated disorders – Neurological features are severe and slowly progressive with episodes of regression associated with provoking factors. Features may include; psychomotor retardation, spastic diplegia, ataxia, epilepsy, autism and leukoencephalopathy. Leukoencephalopathy predominantly involves the subcortical and deep cerebral white matter and the middle blade of the corpus callosum.
Dysmorphism
All CLPP related disorders – Affected individuals may have short stature and microcephaly.