RT Journal Article SR Electronic T1 Editorial JF Journal of Medical Genetics JO J Med Genet FD BMJ Publishing Group Ltd SP 161 OP 163 DO 10.1136/jmg.21.3.161 VO 21 IS 3 A1 C A Clarke YR 1984 UL http://jmg.bmj.com/content/21/3/161.abstract AB