SPG11 is an autosomal recessive gene located on chromosome 15. There has been little experience with it in Australia but on a world wide scale it is an important disease within the scope of Hereditary Spastic Paraplegia. It is sometimes referred to HSP-TCC with TCC standing for thin corpus callosum.
Patients exhibit the common spastic paraplegia symptoms but it is also associated with cognitive defects caused by a thin corpus callosum – the mass of white matter under the top of the scull that joins the left side of the brain to the right side and that houses a bundle of axons beneath the cortex.
In 2000 Japanese scientists recognized a link between the chromosome location 15q13-15 and the thin corpus callosum using Magnetic Resonant Imaging (MRI) technology. Chinese scientists later confirmed the findings and concluded from their study:
“The main clinical features of HSP-TCC include slowly progressive spastic paraplegia, mental impairment during the second decade of life and an extremely thin corpus callosum as shown on cranial MRI scans.”
Since then similar findings have been published from Turkey, Oman, Israel, Germany and Brazil and the location of SPG 11 refined in these later studies. In several papers the association with consanguinity (blood relatives) was noted.