Alvim-Soares et al. (75) found that a HMCN1 polymorphism (rs2891230) is associated with PPD symptoms, and the heterozygosity for this single nucleotide polymorphism (SNP) was associated with an increased risk of PPD, in a sample of 110 randomly selected, unrelated Brazilian women of European descent, assessed at 8 weeks postpartum. Here, HMCN1 is linked to progressive pseudorheumatoid arthropathy of childhood.