The de novo mutation of KIF1A gene as the cause for Spastic paraplegia 30 in a Turkish casein a case

Background Hereditary spastic paraplegias (HSPs) are a group of clinically and genetically distinct neurodegenerative diseases characterized by progressive stiffness and lower limb paralysis. There are currently up to 79 loci [spastic paraplegia [SPG]] known to exist. A family with early childhood-onset HSP was reported due to a homozygous mutation in KIF1A (Kinesin family member 1A) in 2011. KIF1A , located on the long arm of chromosome 2 [2q37.3], is the cause of its regulated sensory and autonomic neuropathy type 2 [HSAN2]. A heterozygous KIF1A mutation has also been implicated in nonsyndromal intellectual disability [mental retardation, autosomal dominant 9:MRD9]. Case presentation Here, we describe a boy who was 13 years old who had minor mental impairment, epileptic seizures as he grew older, hypotonia in infancy, and finally, spastic paraplegia [autosomal dominant inheritance]. Exome analysis detected a de nova heterozygous KIF1A mutation [c.1031c > t p.thr344met] in this male. Conclusions The alteration identified by the patient's exome study substitutes neutral and non-polar methionine for neutral and polar threonine at the 344th codon of the KIF1A protein [p.Thr344Met]. According to the literature searches, it was observed that the variant was present in at least one individual. We believe that this change in the motor region of the gene causes spastic paraplegia and mental retardation in individuals with clinical features of autosomal dominant KIF1A -related conditions and also causes previously unidentified epileptic attacks. The conformational change in the protein structure [structural, mechanical] disrupts the protein's function. Therefore, we consider it a pathogenic variant.