Clinical Characteristics

Individuals affected by BTOP generally present with epilepsy characterized by complex partial seizures, visual hallucinations, and secondary generalization. Temporo-occipital polymicrogyria can be seen on brain imaging. Psychiatric anomalies such as behavioural problems and aggressivity are also common.

Individuals affected by CMT4J present with both proximal and distal asymmetric muscle weakness. Motor and progressive sensory dysfunction is common. EMG studies show chronic denervation of proximal and distal muscles. The phenotype is variable, and the disease onset ranges from early childhood to late adulthood.

Individuals affected by ALS11 present with adult-onset motor neurons findings such as asymmetric muscle weakness.

Individuals affected by YVS generally present with structural brain anomalies such as extensive neuronal loss and diffuse atrophy affecting the cerebellar vermis, corpus callosum, basal ganglia, and frontal lobes. Sparse and pale hair, and facial dysmorphic features (including protruding eyes, anteverted nostrils, short philtrum, short upper lip, labial-gingival retraction, high arched palate, micrognathia, low set/dysplastic ears, and loose skin in neck) are common. Individuals show skeletal anomalies consisting of wide fontanelle/sutures with calvarial dysostosis, aplasia or hypoplasia of the clavicles and phalanges in the hands and feet, and absence of thumbs and halluces. Other radiological findings include of pelvic dysplasia and absent sternal ossification center.