Severe Infantile Axonal Neuropathy with Respiratory Failure Caused by Novel Mutation in X-Linked LAS1L Gene

Agnieszka Stembalska , Małgorzata Rydzanicz (1) , Wojciech Walas , Piotr Gasperowicz (1) , Agnieszka Pollak (1) , Victor Murcia Pienkowski (2, 1) , Mateusz Biela , Magdalena Klaniewska , Zuzanna Gamrot , Ewa Gronska , Rafal Ploski (1) , Robert Smigiel

1 Medical University of Warsaw - Poland
2 MMG - Marseille medical genetics - Centre de génétique médicale de Marseille

LAS1L encodes a nucleolar ribosomal biogenesis protein and is also a component of the Five Friends of Methylated CHTOP (5FMC) complex. Mutations in the LAS1L gene can be associated with Wilson–Turner syndrome (WTS) and, much more rarely, severe infantile hypotonia with respiratory failure. Here, we present an eighteen-month old boy with a phenotype of spinal muscular atrophy with respiratory distress (SMARD). By applying WES, we identified a novel hemizygous synonymous variant in the LAS1L gene inherited from an unaffected mother (c.846G > C, p.Thr282=). We suggest that the identified variant impairs the RNA splicing process. Furthermore, we proved the absence of any coding regions by qPCR and sequencing cDNA using amplicon deep sequencing and Sanger sequencing methods. According to the SMARD phenotype, severe breathing problems causing respiratory insufficiency, hypotonia, and feeding difficulties were observed in our patient from the first days of life. Remarkably, our case is the second described patient with a SMARD-like phenotype due to a mutation in the LAS1L gene and the first with a variant impacting splicing.

Domains: Life Sciences [q-bio]; Genetics; Life Sciences [q-bio]; Human health and pathology

Agnieszka Stembalska, Małgorzata Rydzanicz, Wojciech Walas, Piotr Gasperowicz, Agnieszka Pollak, et al.. Severe Infantile Axonal Neuropathy with Respiratory Failure Caused by Novel Mutation in X-Linked LAS1L Gene. Genes, 2022, 13 (5), pp.725. ⟨10.3390/genes13050725⟩. ⟨hal-04035054⟩