A homozygous p.Val120Leu (c.358G > C) SOD1 mutation led to slowly progressive amyotrophic lateral sclerosis in a Brazilian family

Abstract

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease usually associated with severe weakness and death within 2–5 years. SOD1 mutations cause hereditary ALS in autosomal dominant and rarely in recessive pattern. We describe a new phenotype of slowly progressive fALS due to homozygous SOD1 mutations (c.358G > C, p.Val120Leu) in a Brazilian family. We reviewed the medical chart and interviewed the index patient and other relatives. A 41-year-old man developed weakness in his legs, leading to frequent falls, followed over the next few months with progressive arm fasciculations and muscle atrophy. The SOD1 enzymatic activity in erythrocytes was slightly decreased. A genetic test panel disclosed homozygous SOD1 mutations (c.358G > C, p.Val120Leu). His asymptomatic parents also carried one mutant allele and 2 brothers and a sister had died with ALS. We reported a new family with homozygous SOD1 mutation and slowly progressive ALS course. Further studies are necessary to confirm whether this mutation can also lead to disease in heterozygosis with incomplete penetrance.

Keywords:

• Amyotrophic lateral sclerosis
• superoxide dismutase-1
• homozygosity

Declaration of interest

The authors have no relevant financial, intellectual or other competing interests about the current manuscript. Dr. FAA Gondim has received several research grants and research scholarship from the Brazilian Research Council (CNPq).

Author contributions to manuscript

JMAF and FAAG carried out the design, conception, data collection and interpretation, wrote the original manuscript, revised and approved the final version.

Additional information

Funding

This work was supported by research grants from the Universidade Federal do Ceará.