Of particular note, GRCh38 includes 35 different representations for the immune-related leukocyte receptor complex on Chromosome 19 (Pyo et al. 2010) and two additional haplotype resolved paths of the highly variable and complex SMN1-containing spinal muscular atrophy (SMA) region on Chromosome 5 (Schmutz et al. 2004). The gene discussed is SMN1; the disease is proximal spinal muscular atrophy.