The most common form of autosomal recessive hereditary spastic paraplegia (HSP) is caused by mutations in SPG11/KIAA1840 gene, which encodes for spatacsin. The clinical presentation of SPG11 is characterized by cognitive impairment, peripheral neuropathy and a thin corpus callosum in brain magnetic resonance imaging. We identified a novel homozygous nonsense mutation (c.6082C>T [p.Q2028]) in exon 32 of SPG11 in Korean siblings. Our findings suggest that this novel homozygous mutation in SPG11 is associated with HSP and with dysgenesis of the corpus callosum.

Citations

• Hereditary Spastic Paraplegia Type 11—Clinical, Genetic and Neuroimaging Characteristics
  Justyna Chojdak-Łukasiewicz, Katarzyna Sulima, Anna Zimny, Marta Waliszewska-Prosół, Sławomir Budrewicz
  International Journal of Molecular Sciences.2023; 24(24): 17530.     CrossRef

Background
In general, motor neuron disease comprises combined upper and lower motor neuron diseases, pure lower motor neuron diseases and pure upper motor neuron diseases. The term lower motor neuron disease (LMND) may be used for all diseases in which only lower motor neuron signs are found. Methods: In this study, we investigated clinical and electrophysiological features in patients with sporadic LMND. In order to exclude patients who had amyotrophic lateral sclerosis, only patients who had had the disease for at least 4 years were selected. The patients were then classified into three groups based on the identified pattern of weakness as shown in the registry. Results: The patients with LMND were categorized into groups of generalized weakness (group 1, two patients), asymmetrical weakness of the arms (group 2, 31 patients) and asymmetrical weakness of the legs (group 3, four patients). Analysis of the results showed that the distinguished features of group 1 include, an older age at onset of the disease, more severe weakness and greater functional impairment. In addition, the results also show that the prognosis of sporadic LMND seems to be favorable and clinical abnormalities were confined to one or two limbs in most patients classified by group 2 and 3. Conclusions: The clinical phenotypes of the different subgroups described in this study may help to differentiate the several forms of LMND. Prospective studies are however needed to investigate whether specific clinical or electrophysiological variables may help to identify patients with a more benign form of LMND.