sequencing of a family with flail arm syndrome

Mutations in hnRNPA1 encoding heterogeneous nuclear ribonucleoprotein (hnRNP) A1 are a rare genetic cause of ALS. To further raise early awareness of this variant subtype of ALS, herein, we described a Chinese pedigree with hnRNPA1-related FAS, which showed great clinical variability among the intra-familial members. Detailed clinical evaluations, muscle biopsy, and whole-exome sequencing were performed in the proband. Exome sequencing identified a documented heterozygous variant in hnRNPA1 gene c.1018C>T (p.P340S), which co-segregated with disease in the family, while the proband's daughter was an asymptomatic mutant carrier.