Interacting with AP1 complex mutated synergin gamma (SYNRG) reveals a novel coatopathy in the form of complicated hereditary spastic paraplegia

Background: Today, it is known that about 80 genes are involved in the etiology of hereditary spastic paraplegia. However, there are many cases whose etiology could not be determined by extensive genetic tests such as whole-exome sequencing, clinical exome. Methods: Candidate genes were determined, since no clinically illuminating variant was detected in the whole-exome sequencing analysis of three patients, two of whom were siblings, with a complex hereditary spastic paraplegia phenotype. Results: The p.Leu1202Pro variant in the SYNRG gene in the 1st and 2nd cases, and the p.Gly533* variant in the 3rd case were homozygous. Discussion: We suggest that the SYNRG gene interacting with AP-1 (adaptor-related protein) from the AP complex family may cause the complex hereditary spastic paraplegia phenotype with extensive clinical spectrum. It may be important to evaluate SYNRG gene variants in patients with hereditary spastic paraplegia whose etiology has not been clarified.(c) 2022 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.