title: Sex ratios and age at onset in probands and secondary cases in the spondyloarthropathies.
authors.forename: W H
authors.initials: WH
authors.lastname: James
mesh_terms: D017668:Age of Onset; D005260:Female; D006801:Humans; D007592:Joint Diseases / Q000453:epidemiology* / Q000235:genetics; D008297:Male; D012744:Sex Ratio; D013122:Spinal Diseases / Q000453:epidemiology* / Q000235:genetics