Hereditary Spastic Paraplegia ( HSP) is a rare neurodegenerative disease, affecting approximately 0.3 in 100,000 individuals. It is characterized by progressive spasticity and distal weakness. There are many genetic mutations that can cause HSP. We are discussing a family with HSP caused by the Atlastin1 mutation with manifestation of sensory motor polyneuropathy mimicking Charcot Marie Tooth disease.
In our case, The mother a 54-year-old, presented with a known diagnosis of Charcot Marie Tooth disease and seeking care for her daughter who she believed had symptoms suggestive of the same disease as her. She presented with abnormal gait and and needed crutches to walk, hand weakness and muscle atrophy with some contracutres and deformities, she also complained of loss of sensation in her fingertips. The the daughter and two sons who are 30, 22, and 21 years old, respectively all had similar manifestations with distal weakness and progressively increased tone. On neurological exam, they showed difficult to elicit reflexes and a positive Babinski sign . Additionally, they had underdeveloped muscles in their extremities and difficult ambulation with increased tone . Genetic testing confirmed the diagnosis of HSP with a novel ATL1 pathogenic variant. On the other hand, their electromyogram/nerve conduction studies ( EMG/NCS): showed evidence of low amplitude, slow conduction velocity, and absent sensory responses ( SNAPs). In the third generation: three sons and a daughter, who are born of the daughter from the second generation, were 9, 7, 2, and 1 years old, respectively. The oldest three demonstrated the same presentation and symptoms as their mother, apart from hyperreflexia, with the same genetic testing and EMG results, however showing preserved SNAPs with slow conduction velocities. Genetic testing revealed a novel ATL1 mutation, c.1040 (p.met347lle), in a family with childhood-onset axonal neuropathy and hereditary spastic paraplegia. This presentation reflects the importance of long-term follow-up for neurological manifestations and correlation with the evolving clinical picture